1) There's no recruitment on to the 737 at LGW, the fleet is in surplus already. New entrants will go to the A320, 777 or 747. The company would like type rated pilots to go to the long haul fleets, but strangely enough none are applying. There is still immense demand for a 747 position within the company so I'd expect the majority of new DEPs to go the 777 or A320 where they're needed most.
2) Dunno off the top of my head.
3) New pension plan is gash. Its a defined contribution scheme, you pay a bit, the company pays a bit, then at the end of your career you take all the cash and buy an annuity, which I think is a sort of contract for another company to pay you £X per year until you die. I think current annuity rats are around £100K to buy a £3K p.a. annuity, so work out how many millions you'd need to save to retire comfortably. The BA contribution is 12% of pensionable pay which is only actually about 75% of basic, so the real contribution rate is 9%. This is significantly lower than Virgin and GB.
4) About 200 I think.
For your next set of questions:
1) Probably about £3000pcm at a rough guess.
2) Currently at least 10 years short haul and 15 years long haul. If the retirement age restriction is lifted in 2006 then add a minimum of 5 years to that. Bear in mind that there are probably the best part 1000 pilots in BA who are 30 or younger. They will get a command before you and if you are over 30 then they will also outlast you in BA.
If all you want to do is long haul then go to Virgin. Fly less hours with better cabin crew and you don't get the constant sh1t you get flying for BA.