I agree with many here who consider themselves as wanting this team to be as bad as possible this year that adding players this year just to get marginally better is a poor strategy.
If trades are to be made, and I really don't think Danny is going to make any this season(in the off season, that's another story), Danny will make them to improve this club long term, not short term. Given what he has seen from the development standpoint of players like Crawford, Sullinger, Bradley, Olynyk, Pressey, Faverani and even further development as team players making their game more well rounded like Green and Bass and Lee, I think Danny will be happy to let expiring contracts(Bogans, Humphries, Brooks) expire, add 2 first round picks to this team along with a fully recovered Rondo and see what we have next year with farther development of the youth.
Sullinger looks like he has All-Star(Kevin Love Like) ability to be a major player on a championship squad. Rondo has already proven he can be the man for a team with his all around game and will to win. Bradley is rounding into one of the better pure shooting guards that also happens to be a major difference maker on the defensive end(I still say he has a DPOY run in him one year). If Olynyk and the two picks, which I feel will be very good to maybe one being great) develop, this team is going to be a strong playoff team for years while adding lottery youth from Brooklyn's picks every year.
I'm not sure free agency or a major trade will be necessary but if it turns out Danny can land a Durant because OKC can't afford him anymore or Anthony Davis because Davis hates New Orleans, Ainge will have the picks and youth to make such a trade or sign and trade.