I think the first one is iffy simply because the Raptors probably wouldn't trade DeRozan and Gay, especially if they only get Shannon Brown back at that position. It also doesn't make sense because they then would gain Dragic add him to the PG position and you have Lowry and Dragic both competing for minutes. Same situation with Gortat and JV. If JV is still the starter that works, but you have to be careful in stopping JV's growth as a player by moving him to the bench.
The second trade definitely doesn't work because of the talent difference, as well as not really helping the Rockets. They get smaller in this trade by losing Asik, which leaves their front court at Terrence Jones, Greg Smith, Donatas Motiejunas, and Marcus Camby. They truly need stretch PF, so if they trade Asik it would be for someone who can stretch the floor, like Ryan Anderson. Not to mention that Gerald Green gets lost in the back court shuffle of the Rockets. Maybe try to trade the better Morris and Green.
This is an interesting trade, but I doubt the Celtics would want to take Brandon Jennings and his ego, especially without KG and Paul Pierce there to control it. If it was 2 years ago maybe, but Jennings on this Celtics team would be a disaster.