I like your picks / analysis.
I'm going to base my answer purely on the playoffs (as I feel that's what counts the most) and my picks are...
1. Clippers:
The Clippers were a tough out last year as it is. Adding Pierce & Smith pushes them to a whole other level. Pierce adds an extra clutch scorer that the defense must respect, which takes a lot of pressure off CP3 (who was often relied on far too heavily last year). Josh Smith at his best is an All-Star caliber talent, and when he's motivated (i.e. playoff time) he can dominant on both ends of the floor. This is a deep, tough, talented, experienced and well coached team - they will be VERY hard to beat.
2. Spurs
This is a long shot, and depends entirely on how gracefully Tim Duncan and Tony Parker age (and their ability to remain healthy) in this upcoming season. If Duncan can be as productive as he was last year, then the Aldridge/Duncan front court will be an absolute force to be reckoned with. Kawhi Leonard is going to be consistently excellent as always. Green will do what he does. If Parker can continue to play at (or near) the level he played at last season, then that's a great starting lineup. Bench depth may be a question mark, but they'll be real tough regardless and there might not be any coach who gets the most out of limited talent like Pop does.
3. Warriors:
They may be the defending champs, but I must admit I wasn't entirely convinced. A severely crippled Cavs team (led almost single-handedly by Lebron) was able to put a real scare into a deep and talented Warriors team that was supposed to be the best team in the league. Was this a sign of mental weakness on the Warriors part, or was it merely a testament to Lebron's greatness? That, combined with Curry's inconsistency in the series, leaves me only somewhat convinced by the Warriors. The loss of Lee (who was a major contributor for that team) doesn't help their case either.
4. Rockets
The Rockets added Ty Lawson, which is huge for them. They also lost Josh Smith, which could be similarly huge - he was a major reason for them being such a tough out in last year's playoffs, and so I get the feeling they'll be at a similar level overall to last year. If Dwight Howard can stay healthy however, that could change everything. Howard and Harden are a match made in heaven.
5. Thunder
The Thunder have too many question marks. Will Westbrook's play last season draw questions about who is the #1 man in OKC (much like the Kobe/Shaq saga in Lakers years past)? Was matching Kanter to a max contact a wise move? Will the loss of Reggie Jackson hurt their long-term depth? Will Durant return at the same level he was at before the injury? Then there's the fact that the Thunder have always been a better regular season team than they have as a playoff team. They've been among the top 2 or 3 most talented teams in the league for years now, yet have only made the finals one (where they got handily dominated by the Heat). I believed the Thunder's hopes of a title left when they traded out Harden, but time will tell.