Here i'll even organize the shit for you:

1: Has anyone ever grown on an incline?

Yes - as long as its well-rooted and doesn't flood you should be fine. I'd worry more about sun exposure and make sure its the right side of the mountain

2: How hard is white rhino to grow outdoors?

Sorry can't comment

3: Do baking soda and vinegar work well enough to be ok with?

I use Lemon juice instead of vinegar, but yes, they work fine - just need to figure out what your source water is and play around with measurements til ya get it right. ie 1 gallon of my well water + 1/2 tsp Lemon juice = 6.5 PH every time, dont even have to check it but a couple times a year to make sure the well didn't change

4: Does bottled water have an ok ph already?

Depends on the brand - whatever you decide to use , test it and stick with the same water throught the grow for consistiency

5: For anyone who lives in california, when does the veg period begin and the flowering period start?

Depending on where you're at it can start as early as Feb-Mar. Flowering will start after 6/21 sometime, all depends on your exact geographic location. Try looking up your zone and growing tips/times for tomatoes from like the Farmers Almanac, for a start