His morning dilatoriness sounds entirely typical of his age. With my ds (7) I never find I can leave him for 30 minutes and find any progress. I check on him every 10 minutes and chivy him on. (I would confiscate any toy that got in the way of getting ready for school, but that's a rule he knows about and accepts.)
All his mates' Mums also moan about how their sons take forever to do things (though IMHO ds takes the biscuit).
So this part of it doesn't sound so unusual.
What does come through very clearly from your post, though, is that there is a lot of tension in your house and that you are stressed and exhausted to the point where even fairly normal behaviour is just too much for you. Also, the language you mentioned your sons using, and your ds1's violent behaviour seem to point to some more serious stress.
Has your ds1 been checked out for the obvious developmental disorders? Has he been through any trauma (like a messy divorce, or bereavement)? Sorry if you have mentioned this in earlier threads. It may be that he has anger that he needs to be taught how to express.
Do you think ds2 could be suffering from dyspraxia?
But most important- are you getting any help? Is there anyone who can take the boys off your hands for a while so you can get me-time? DO you have anything in your life that is fun? Like a hobby, or a circle of friends? Have you been to see your GP?
Sorry, lots and lots of questions, but I really do hope you can get some help.
As for them only playing up with you- I'm afraid that's what you can expect if you are the person who means most to them. So very important to get you the support you need.