In "Classic Styles" when they say Munich LME is this basically the same as Amber?
No, it's not. Don't substitute amber for munich. Munich LME is a specialty extract made from Munich malt. Amber LME is typically made from some pale base malt (2-row) and some amount of crystal malt. It has a completely different color and flavor.
I am also wondering about the importance of Pilsener LME in the recipes. I don't have access to that extract but I can get extra light LME.
It's not a deal-breaker, but if you can find some it's probably worth the extra effort. Pilsner malt has a different flavor from domestic 2-row, which is what your typical extra light LME is made from. That said, it's really only worth the effort (IMO) if you're not going to be using a bunch of specialty malts with it that will overpower the base malt's flavor. So, if you're making a Pilsner, or maybe a Belgian Blonde.
Incidentally I am looking for a recipe to use my Wyeast Belgian Abbey II liquid yeast. I hesitate to go for the recipes in Classic Styles for Belgian beers because they ask for Pilsener extract. Any thoughts? They also call for several packets of liquid yeast which gets expensive fast!
You need fewer vials/yeast packs if you're making starters of sufficient size, and even better is to use a stir plate. A vial/yeast pack has about 100 billion cells in it on the day it's made, and as the days creep on, some of those yeast cells die off, even if you're storing it properly in a fridge. So, your best bet for pitching appropriately is to use very fresh yeast, and make a starter with it. The most basic starter you can make is putting some 1.035-1.040 wort (don't fill it completely--maybe 1/2 to 2/3) into a 2L bottle and pitching your vial/smack pack into that, and then just shake the hell out of it whenever you walk by and see it sitting there. That is called "intermittent shaking" and works fairly well at growing the yeast. Don't keep the cap screwed on tight! The CO2 needs to vent or you will blow up your bottle.
http://www.yeastcalc.com/
For Belgian beers in particular, it might not be *as* necessary to pitch the right amounts, as the extra esters and phenols you develop as a consequence of underpitching might be construed as appropriate for the style, but you can still run into issues with your beer not attenuating as much as it ought to or even stalled fermentation, and with other potential off-flavors developing that
aren't to style. You can get away with it, but if you're just starting out you're better off learning how to make appropriately-sized starters and pitching healthy quantities of yeast. And, if necessary, that extra $6 can mean the difference between a batch that turns out "ok" and a batch that turns out great, assuming you are also controlling fermentation temperatures adequately.