Strat combat clarifications

[Pocus]

Can somebody enlighten me on the following points:

1 - if you set a fleet, but have ships which break formations, can I assume that the fleet strategy has no meaning?

2 - Why a troop transport on invade planet wont head toward the planet until the place is cleared of all defences? How to perform a strategy of assault transports which try to unload troops even with defences firing (I'm speaking of strat combat here!).

3 - Why the computer decide that a fleet which has the following orders:
a) torp ships with optimal fire range
b) transports on capture
ships break formation, fleet order capture planet.

Ok, so the torp ships fire on the planet till there is no defences, then they stop fire. The transport move into position. What I dont understand is how the computer know that he must make the torp ships cease fire? Do he scan all your ships, see a transport on invade planet, then decide that he is better in stopping fire? Thats strange because without the transport, you will glass the planet.