I would not introduce fringe players or play moderately experienced guys with moderate success.
Guys like Carberry and Sidebottom doing well against Bangladesh are going to cause more headaches than solve problems.
Id look to focus on player development (eg guys like Broad, Onions, Trott), backbone (Strauss, KP), and blooding young players that may be around for 10 years and can slot into a few spots surrounded by experienced pros.
Ie the future combined with the present core. Id keep Prior as Bangladesh would be a change of environment to keep in. Not a place for middle of the road players (eg Bell and Anderson) or guys that IMO cant cut it (eg Wright, Saj, Bresnan) to pad their stats. IMO the England captaincy is a fulltime job
My XI
1. Strauss
2. Cook
3. Trott
4. KP
5.
6. Prior
7. Rashid
8. Broad
9. Swann
10.
11. Onions
Ive left 5 and 10 blank for a young batsman and bowler that the selectors think will be around for a long time. Maybe Denly, Bopara and Finn etc. Ive left them blank as I dont have my finger on the pulse enough to assess the best young prospects.
A player such as Sidebottom would add Test experience to that side. As another poster said the side I mooted would be handing a few Test debuts out, therefore the inclusion of someone like Sidebottom would be essential.
I would certainly take Bopara along, and prbably start with him in the Test XI. I also agree a few younger players would also benefit from the trip. As you mention Finn or Denly would more than likely be going in my squad.
Ian Bell would certainly go for me, he should have regained confidence, and now has the chance to really try and help solidify his position, let him continue scoring Test runs, he should not be in need of a rest either.
I understand your theory of combining player development with backbone and the future, and I think the changes I would make would agree with this theory, perhaps barring a couple of backbone players. But you cannot underestimate the benefits of giving players a bit of a break, ask Ponting, ask Collingwood, ask most international players. This, imo, represents an opportunity to allow some of the players in need of a break just that.
As for the captaincy, interesting this one, I think it all depends on the state of Strauss. His job is clearly stressful, tiring, both physically and mentally, and if he needs some time to come back for the summer fully refreshed, then I don't have a problem with that. Greaqt experience for Cook. Cricket sides will increasingly use squad rotation to keep players fresh, the players selected in their places will have the opportunity to play for their country, enhance their chances of selection in the future, the make-up of the side, and the actual selection of players I am not 100% sure of yet, but will give it more thought.