I would replace the screws with stainless, just because it's inexpensive to do and they won't rust on you.
Skate on the temp mount, you will NOT hurt anything, I promise. You can actually do quite a lot of skating before it's a "problem" that you don't have permanent mounts. Since you're not really jumping and not doing advanced spins, there's really nothing to worry about. Even jumping and spinning in temp mounts is fine - you just wouldn't want to do it for months and months. Where I am, most of the time people skate on the temp mounts for anywhere from 2-6 weeks, then have the permanent screws put in... usually skates doing the harder jumps (doubles, triples) will get the permanent screws in faster.
While on the temp mounts, check the screws to make sure they are snug every time you skate - when the soles are new, the leather can compress a little bit with skating and the screws can become a little loose.
If you feel like your blades are not aligned, you can loosen the screws and nudge the blade over yourself - you don't need a pro to do this, but I would not make big adjustments. Just be careful when re-tightening the screws that you don't strip them. You can also ask a coach to check the alignment - they'll simply watch you skate and may ask you to try a few things, and can tell if you need them moved over one way or the other.
I can actually tell by just wearing boots off-ice with guards if the blade is in the right position for me.. you can probably feel it if you try to stand on one foot, if you find yourself falling to one side or the other.. moving the blade just a tiny bit can make a huge difference. The last two pairs of blades I've adjusted off-ice like this, and they only needed very minor repositioning once I had skated on them.
Like I said before, you can sno-seal the sides of your soles yourself - you don't need to pay someone to do what you can do yourself for $7 with a hair dryer
The bottom of the sole on Jacksons is sealed and needs no special treatment.