I normally don't get involved and let the league vote decide, but I would be wary of Options 1, 2 and 4. Here are basic reasons why.
1.) Keeping as is allows for 'Super' teams to form if rebuild teams are not careful and sacrifice too much cap to more power teams who want great players and max contracts.
2 Really impedes dealing and the idea of trying to mirror the NBA. Could anyone imagine the NBA or any sport ever not allowing cash to be exchanged in deals? 2 words: No, no.
4.) 10M is too little as a bunch of players on resign alone will exceed 15M or so, and if you have a hard cap of only being able to deal away 10M, it can b hard to deal and stay under cap if you have a max contract player.
I think the best option honestly is, as a league agree that any team may deal up to a certain percentage of cap away for a max of 3 years, but then must return to normal cap for at lest 2 yrs after that lowering. Also, any team may have up to a certain percentage above the current cap for 3 yrs, but that percentage is around or just lower than the amount any team may deal away. Same years restriction will apply.
I would say for example, if you want to have a lower cap, and the cap is 100M, you may go no lower than 80M, and on the upper bound, say 115M, to keep a competitive balance.
Maybe this doesn't make total sense, but could be a ay to allow cap deals and keep a competitive balance.