Fighters vs. Heavy Fighters - another newbie question

	I've been thinking about using heavy fighters instead of
standards
for the same reason that I like the idea of using L2 screens on my
ships:	The extra survivability gives me a warm fuzzy feeling, even
if it isn't quite as efficient.

	How many of you use heavy fighters regularly?  If you add in 
the carrier cost, the upgrade to a heavy doesn't seem that expensive
for what you get.  Anybody disagree?

	How do you feel about using heavy interceptors or heavy attack
fighters?  Are there any rules against mixing variants like that?  I
wouldn't try mixing a heavy-interceptor-attack variant, but heavy or
fast seem okay to mix with the other options.

	What's the best way to use fighters?  Depending on who I face
I'll be fighting anything from a standard FB fleet with a few ADFC to
a custom fleet with a fairly strong area defense net.  Should I hold
back the fighters until I can whittle down the escorts?  Go after the 
escorts themselves?  Concentrate on smaller ships that are outside
the main defense net?

Thanks,
Joe