I'm not sure how many school events you shot, but generally, what (imo) are most important for school events are:
1. Normal zoom lens (kit lens is fine, a f2.8 one like a Sigma 17-50 f2.8 OS HSM would be great) - you need wide and normal
2. Flash with diffuser or bounce card - many events use school hall, and flash is usually needed, even with a f2.8 lens
3. Tele zoom (55-200/55-250 would be fine, 70-200 f4 if got more budget, 70-200 f2.8 IS if too rich)
The rest (fast prime, batt grip etc) are optional, and not the most important - flexibility is important.
But of course, you have other interests in photography, which is fine.
1. Battery grip: really not needed unless you have a heavy lens. If you need better ergonomics a higher end body would be better than low end body + grip
2. Spare batteries: usually not needed unless on a full day shoot
3. UV filters: important, yes, but if your current lenses already have filters, then you'll be wasting your money getting more filters
4. Macro converters: you need a flash first, if you are going into macro
5. A 50/1.8 - you have a 50/1.4
6. Kit lens - you should have bought it in the first place, a general zoom lens is always great (not to mention its range is the most used)
7. Webhosting - you are not getting clients yet, so use flickr first, then when you actually have better shots, look into paid webhosting
Just trying to help, there is really no point getting all these spare equipment when you don't even have what is most important. You need to prioritise, not get anything that reviews say are great. And by the way, most review sites say the kit lens is the most value for money lens which provides excellent image quality for its price. Just saying.
