Forward tilt after running jolt is probably fine. I'm not sure exactly what it covers, but could be a decent option if the jolt hits and you don't really have enough stage to nair through them, so ftilt will hopefully send them offstage and put you in a good position. I generally nair after jolt because if I fullhop it it covers them trying to jump over jolt, or if i shorthop it it covers people shielding (or getting hit by) jolt. If it connects, I can potentially follow with a jc usmash or a techchase (or another nair, whatever makes sense based on their percentage) using my momentum to keep on them. Jolt doesn't have to hit to be good (though that's the main hope with it). Jolt can lock someone down, reducing their viable options and giving them something else to worry about as you approach, which can help with the success of your approach. Ftilt after jolt seems like a safe-but-low reward option most of the time, but I can see it being useful in the situation I mentioned.
I used to uptilt after nair occasionally, but now I don't like it as much. It's probably fine to throw in occasionally, because it has a slightly different timing than your other followups (uair, nair, dashdance usmash/grab). It comes out slightly slower than your immediate aerials, so you can catch people (as you mentioned) who try to jump/wd out of shield slightly delayed (so they shield the likely-rising-uair coming after). In that position (you being right behind them and hitting their shield with the early hitbox of utilt) It's safe against some chars and less safe against others. It doesn't have a lot of shieldstun, so they're likely to be out of shieldstun right as your utilt ends. Against Fox/Falco I'd be pretty weary of this because they can shine out of shield you before utilt comes out. Against Marth I could have maybe done it a couple times, but I was afraid if he shielded it he could dashaway->dashback and threaten grab if I didn't dash away immediately after utilt (and it might still work because Marth's grabrange is bonkers). If I get utilt on Marth I don't think it'd lead to much anyways, probably like utilt->uair->nair or just utilt->nair. Just rising uair after the nair on shield gets me about the same benefit while also being safer. Successful utilt on Fox could lead to some sweet combos, but again it's rather risky and rising uair covers almost all the same stuff while being safer.
Thanks for watching though! I'm always up for constructive criticism/discussion on what I could do better. I haven't gotten to watch my matches much recently, and I'm noticing a lot of things I want to start doing differently (mostly not messing up tech all the goddamn time lol).