You don't have to go to the metaplanes to initiate (though you can), and the Astral Combat skill is fairly low use, since you can just cast mana spells while on the astral (using the Spellcasting skill, which you already want maxed, so AC is basically a redundant skill imo). You do want high INT as INT is turned into REA on the astral (see p. 314) but otherwise, having Astral Combat isn't very useful unless you want to get a weapon focus (which I wouldn't recommend since you don't have the other stats useful for Astral Combat).
Basically, Astral Combat and Banishing are unfortunately narrow skills, both of which are largely obviated by having Stunbolt, good Spellcasting, and a good Power Focus. People will reference the Spirit Index from Street Grimoire as a basic reason why Banishing can sometimes be useful, but (IIRC) it's either an optional rule, or it doesn't matter until you've disrupted like 25 spirits, so either way, it's generally a non-issue, especially if you don't care much about summoning.
Looking at your sheet, I'm going to make a suggestion. INT is your drain stat from your tradition, right? You want this to be maxed, because it makes it less risky for you to take drain while casting spells. Make INT a 6, WIL a 5, drop BOD to 3, and just have STR 1. Or seriously look into having a tradition where CHA is the drain stat (Aztec is awesome but may not fit exactly what you want to do, admittedly).
Making your own foci is just a really difficult path with a lot of opportunities for unpleasant failure, it's much easier to just buy them and have your talismonger upgrade them when needed.
I think you will regret not being able to summon effectively, spirits are the huge force multiplier that mages can bring, but of course that's your call.
