The advantages are:
Keeps Battier's 3pt shooting on the court,
Puts the team's best defenders on the court,
Adds Scola's scoring to otherwise offensively challenged reserve bigs,
Creates possible match-up problems for other teams forcing them to go small whether they want to or not.
The disadvantages I see are:
Rebounding. The Grizz and Rox tried Battier at PF and failed. Not so much because the bigger players overpowered Shane but simply the other team dominated the boards. Shane is not a rebounder. While Artest is certainly stronger,he is not a particulary good rebounder either. Last yr he ave'd less than a rebound a game more than Shane-or McGrady. To avoid getting killed on the glass the Rockets will have to keep everybody in to rebound,making fast breaks that much more difficut.
Offense. While the thought of Ron taking some PF out away from the basket and driving past him has a nice appeal,reality may offer up a different vision. Namely,Ron is not the best decision-maker/passer on the move. One of his strengths is in posting up as he can over-power most 2/3s. Not so w/PFs. And we're basically talking about Ron going 1-on-1,Tracy going 1-on-1,dumping it in to Yao and watching him go 1-on-1,all of which has the rest of the team standing around,which is NOT what Adelman wants out of his offense. Not to mention other teams may simply tell their PF to "guard" Battier,as he does not exactly stay in motion on offense.
Weak-side defensive help. W/Ron at the 4,smart teams would relentlessly attack the basket,trying to get Yao in foul trouble,knowing that there woud be no other shot blockers to worry about.
My view is the Rockets would give up too much rebounding and not gain enough offensively w/Ron starting at the 4. I think Adelman will prefer to keep a standard starting line-up and make in-game adjustments to teams where Ron coud get significant minutes at the 4. so i think he either starts at the 3,or is the 6th man-not the starting PF. My opinion,what's yours?
West C/PF combos-
Spurs......Oberto/Duncan
Hornets..Chandler/West
Mavs.......Dampier/Dirk
Memphis..Like it matters

Lakers.....Bynum/Gasol
Suns.......Shaq/Amare
Warriors..Biedrins/Cast of thousands
Clippers..Kaman/Camby
Kings.....Warm Body1/Warm Body2
Jazz......Okur/Boozer
Blazers..Oden/Aldridge
Nuggets..Overpaid injury waiting to happen1/Even more overpaid injury in waiting2
Wolves...Jefferson/Sidekick to be named
Thunder..Wilcox/Lucky fan in first "hey he couldn't do any worse and we won't have to pay him"