Bitcoin unlimited = Hardfork
Hardfork is quite risky if there is so much debate between community like we have right now.
The point is however, that *undoing* a hard fork, is a soft fork, and undoing a soft fork, is a hard fork.
So while it may *seem* that a soft fork is "softer", in fact, going back is harder.
Community is divided between two distinct solution BU and Segwit
Not really. The community is divided between:
1) bitcoin as it is (immutability)
2) modifications, such as:
a) BU, XT, .... who undo the limit of 1 MB that Satoshi introduced as an anti-spam measure
b) segwit