The exchange menu is fine. I think the people who have a beef with it don't understand what the exchange is for.
When you get a new leve, it shows you its objective and rewards, then asks to exchange leves. What I assume people are missing, is that each leve you exchange (pending that you actually completed it, which puts a 1-star by the title) buffs the rewards of the leve you are obtaining. That's why you can exchange 0-4 leves each time you choose a new one. The only stipulation of course is you HAVE to swap a leve if you have 8 old ones.
Also, the Necrologos levequests are probably the most difficult ones I have done so far, highly influenced by the fact that you have to fight elementals a lot of the time, and the page drop rates are across the board atrocious. I've failed all but one of the Necrologos series so far, two of which were timed out. They've also been the most interesting ones I've done by a good margin.