Is it better for a plant to start it's life in it's final home or should they be transplanted? When is it time to transplant from seed? Should they receive any nutrients when you transplant them? how do you get the right ph for watering plants in soil? Is 7.5 to high of a ph for the soil?

Transplanting is considered better. I'd only plant in the final home if growing outside and maybe not even then.

When the first container is showing a lot roots on the outside of the medium and out the bottom of the drain holes.

You adjust the soil with amendments and/or the water/nutrients going in. People often measure what goes in and what comes out.

Yes, 7.5 is too high, you'd be looking for about 6.5 - 6.7. As I said above you can lower it with soil amendments or by lowering the pH in the water/nutrients that you pour in. Seedlings don't need nutrients for several days though.

Some people think that soil is easiest, I'm not sure that's true...

I germinated seeds 12 days ago 6 out of 7 sprouted now its 10 days after they emerged from their smart pots filled with ffof mixed with fflw and about 30% extra perlitei with 1/2 cup azomite and im wondering what water is best for them? should I water until water drips out of the bottom of the pots? the plants all have the first set of 3 leaves fullly extended , also noticed on one plant little yellow spots forming in the center of the first single leaves

is roots organic soil worth the extra money? and does it really mater what soil you use considering you will end up giving it nutes anyway?

I guess it depends on what comes out of your tap but RO or distilled is often preferred since it should be the same for everyone. Yes, you want some drainage.

Once you start your actual GFP journal you can include pictures that will help us figure out problems.

I have no opinion regarding modern soil mixes, I only use soil outside and I find it lying on the ground.

I'm buying supplies for my grow room , the room is 42 by 46 by 108 I will have one ss400 and utilizing an area at 4 feet off the ground with coated wire shelves set at 4 foot, the first grow will be in a mixture of 1:1:1 roots organic:ffof;fflw with about 40% additional perlite, using flora nova nutes,I will be utilizing a smaller footprint for the grow space the door has been sealed to where there is no light penetration when closed, but I'm not sure what size exhuast I should use or brand ? as I want it to be quiet . I will be growing skywalker og kush and th darkstar with the scrog method
I guess my questions would be what exhaust would you suggest? And would pulling air from under my house work for intake if I put I filter on the intake? Is it best to adjust the water ph with ph up and ph down by g.h. Before feeding the plants? After this first grow I will be switching to a flood and drain system and add in another ss400 so that I can utilize all of my grow space

As I've mentioned in other threads, I always recommend a larger fan than you need and a speed controller to slow it down and cut down on noise. I'm a fan of Can Max-Fan fans and I'd suggest 6-8", which speed controller is completely up to you bu the Can folks might have a suggestion there.

Yes, pulling air from under a house is fine if you have a good filter.

Yes, before. Add your nutrients/additives to the water, stir/mix well, let it set for a few minutes and then adjust the pH. Then let it set a few more and recheck the pH. Check the pH of your run-off/drainage and that'll let you know of you need to go a little higher or lower next time.