Jefferson vs. Love
Who do you keep and why? Does one have more value on the court? More value in a trade? Criteria can be anything you want, but you only get one of them.
Flynn vs. Sessions
Both relatively young, and both with areas to improve. Again as above, you can only have one, which one do you want?
Darko vs. No Darko
We only saw him for a limited number of games, but thats all Kahn and Co. get too. This assumes he is willing to sign, but does not make any assumptions about his contract. If his contract would be a deciding factor for you, then state what your break point is in years and dollars. At what point do you say "sorry that's too much" and walk away?
If anyone else has some more ideas for it plesae feel free to toss them in. Now for my answers (which I fully admit can be proven wrong over the long run):
Jefferson vs. Love
I take Jefferson every time. I understand his price is higher and "he isn't as good a fit for the triangle" or whatever that means. I don't think the triangle requires every player to be able to sprint down the court (see Lakers with Shaq), but I do think every contending team needs a low post threat that when called upon can get a reasonable shot off on the block. I trust Jefferson in that role much more than I do Love. I would miss Love's rebounding, but that's certainly something I can live with because I'd miss Big Al's post presence more.
Flynn vs. Sessions
I pick Flynn. I really like what Sessions has done this year, but I see more potential in Flynn. I think Flynn has better athletic abilities, and when comparing two PGs who I think are similar (Flynn being slightly worse) in production the athletic abilities tip the scale. Again this is my perception, and I fully admit that stats like PER and WS may say that Sessions is a much better player, but I dont care.

Darko vs. No Darko
I attempt to resign Darko. I admit this depends on the contract, and I think my break point would be 4 years and 25 Million with year 4 being a team option. Anything above and beyond that I think is too long/much.