impulse modification, is this a normal thing or am I more of an idiot than even my wife thinks?

Anyway, FC T2, decided to upgrade to the FD alternator after having a previous and now second belt issue. I had previously looked a few threads on it, so decided I wanted more amps anyway, I’ll just order an FD alternator. Banzai had a handy dual belt kit I could throw on and boom all done, right? Well, the pulley comes, but the alt is back ordered. Looking at the pulley it occurs to me, do I need a second pulley to accommodate the belts elsewhere? Looking at the car, I feel they both must go around water pump.
well, here is the catalyst I need to do the air pump removal I had planned I guess. Or do I have it all wrong?
Have tried to research it, but only new questions and no definite answer.
Question 1: Should I also be changing the water pump pulley? Underdrive? Or is the banzai kit already compensating?
Question 2: Paranoid to damage water pump, how tight on belts? Normal alt belt deflection?

Before you roast me too hard for my ill thought process, yes very new to the car and working on cars, but I really want to do things right! Let you who hasn’t done something this bone headed make the first bash!

Thanks for any help all,
John

Gotcha, thanks very much for input Dak.