Is the shabad Deh Shiva not accepted by some Sikhs as a Sikh Anthem?

It is NOT a Sikh Anthem. For the few very essential reasons:

1) Sikhi is a religion/faith not a country with borders and anthems with anthems. We have ardas and sarbat da bhala and universal brotherhood as our creed, . Our philosophy transcends shiv-sakti and trinities and godheads and the concept of Akal purukh is way way above all the existing thoughts of the time and even today. We cannot regress into puranic ideologies and myths and get embroiled in personalities and images.
2) Ode to shiva is not gurmatt. This is taken from chandi-charitar and is an ode to sakti - truncated/time-limited gods and powers are not our creed.
3) There are definite injunctions against sakat-worship in the AGGS.
I am sure Dya Singh does not mean any which way to degrade or demean gurmatt. Hence, the contents can always be analysed and changed without throwing the baby out with the water! Some controversial banis are the cross
we all carry - it is not limited to Dya singh. Adding new instruments or musical modes is not an insult to gurbani - it is an act of devotion just as "tundae asraajae ki dhunn" was incorporated/recommended by Guru sahib for singing Asa Di Vaar and bringing out its real ambience. Let us not forget 'vaars' were also sung incorporating love-stories and feats of bravery not just religious content.

Where does it say in the bani that we have to use specific instruments to sing praises ?

We have traditions. But music is music and it is a universal language. Hence changes in instruments cannot change the meters of the verse nor the words. If degreedoo is played it hardly takes away from gurmatt! Lets not make presumptions when our Holy bani does not carry any specific guidelines on how Shabads should be sung, interpretations should not be personal but construtive in benefit. They are guidelines not injunctions. The main focus is again the words. Recommendations cannot be taken to mean iron clad dogma.

Did we learn anything from the " Maas Maas Moorkh Chagdeh " issue ? Is Dya Singh encouraging or supporting miscreants who allow the Holy Bani to be placed in places where meat and alcohol is served ?

There is no such thing or place that is polluted. The idea of purity and impurity is discussed at length in gurbani. That place is blessed where my satgur is present..... thus sayeth gurbani. If Dya Singh sings gurbani then the place/audience is blessed. A few months ago in Malaysia , a well known youth group leader was asked a question on eating of meat. He replied " If you are not comfortable with halal meat than just consume eggs and sea food " A young Sikh girl stood up and asked him " Uncle Ji what do you consume and he and his wife replied , " We are vegens " and another Sikh got up and asked " Than Veer Ji why are you encouraging us to eat eggs and sea food " they replied " Oh , that is our choice " :-) get the message I call this parallel preaching with two set of preferences . Some Sikh youth like Rap music , some Reggae so what is wrong if they appreciate the shabad sang to some hindi tune , is this a fast rule in our Holy Bani. Hindi music that is classical in nature or has a good background may not be that bad but the mujra/brothel connotations of movies is not too conducive to concentration and defeats the purpose of listening in the first place - if one is imagining sridevi/rekha pandering to clients on the scene or the heroine is running around trees with the hero in pursuit it does take away from of thought process for us with the wandering minds in the first place! Let us not forget - we aint saints! In one of the Youth Camp call in the US , I read the posting where it welcome the youth with this message : ( maybe not verbatim )
a) " We are not going to ask you to keep your hair "
b) " We are not going to ask you to stop taking alcohol "
c) We are not going to ask you to become an Amritdhari "
and many more of this , What was their goal here ? There is no pressure but when given a chance to teach and explain to this youth , many will come out positive of their religion and the change will come from within. That is a welcome attitude and will win many students willing to learn. A question was asked on dying of hair by a veer from Australia.

What is wrong in dying the hair , be it mendhi or soft colour ?

Bapu Ji's dye their beard , bebeh Jis their hair , I have not heard of anyone dying their armpit hair , now that is a health hazard. If we go by the book , wearing gold on one self is also against the order . There is more that needs to be addressed than this nitty gritty of enhancing one's image with colours. We drive coloured cars , we wear coloured clothes, we paint our house with colours , so what is wrong

If one indulges with a little colour , what say you Mrs. A Singh ?

There is no harm enjoying the bounties of nature/world/modern civilisation as long as one does not hurt anyone. That is why sikhi is not about extremes or asceticism but creed of the householder. The only time an action becomes a burden is when God is forgotten. God has created the world for us to live in and learn not run away from it. We have to seek our own balances in a general framework. Sharias and drilled religion does not always make allowances for us the sinners. Bring on the colour - but not turn into 'gaindae de phul' or run helter skelter at the sight of bibis and their tresses. Bappu Ji will be happy to see Bebeh Ji with Jet black or brown hair looking like Hema Malini , it may add a few more years to his aging life It is between bebe ji and bapu ji for sure!! I am sure such devotion would be appreciable. Bappu Ji's kind of hard message may not go well with today's youth due to the poor peer guidance and the western influence. Be innovative without compromising on our belief's . Just see what is happening at Akal Thakt in Amritsar , " Kissa Kursi Ka if they can change their attitude , we will be a force to be reckoned with. Twilight Zone bappu Ji's are the front runners , it is about time the younger learned sangat took over and infuse new ideas to take our religion to higher plains. Sikh values in Punjab today are declining due to the strong influence of these vulgar Punjabi singers and Bappu Ji's at Akal Thakt are sitting on their THRONE and enjoying the rot and nobody say anything to them. I am not asking for a total paradigm shift but let those walking the talk carry on with their good work and correct them constructively if they have strayed but with sincereity. I do not listen to Dya Singh's music daily but I respect and support him for what he is doing as I would like to sum up that many of us are just " KEYBOARD WARRIORS " and Cyber Critics who will not give others a chance when we ourselves are not able to deliver. Amen to that Dya Singh Ji, keep up your good work without compromising on the teachings of our Gurus , you are being watched by the International sangat and construtive critcism is part of the Sikhi tradition of learning. Anyone who can carry the message to even on fellow human has done more than all of us armchair academics!