Any ideas how SP could do something regarding these??
I think reducing first-time craft requirements to 75 for nemesis would solve most of the problems but still... drop your ideas down below

Bring back the normal nemesis dungeons and run it alongside the survival one
So non- nemesis owner can still work on their craft
And nemesis owner can rank them and try the challenging survival dungeon

I'd be pretty sure that this was SP 's intention all along. They knew what level was achievable and the spending patterns of their customers so they set up a nice little scenario to maximise their chest sales.
The Nemesis cells dungeon probably won't reappear til all the Warmasters have been released (early next year) but you'll have plenty of chances to buy the cells and of course the nagging motivation of a vault full of "oh... So close... Go on.... Go on..."

I will gladly accept the survival dungeon in the meantime. I got 1000 orbs, 30 gems and 10 Elementium before running out of Nemesis. If only I had more Nemesis.....