First time grower- need some experienced insight- troubleshooting guide included

T5s give a lot of lumens per watt. There's no other reason not to use T12s. LOTS of growers use them in veg, myself and my local friends included, and I have seen some really nice results- big, healthy, flat mothers trained short and wide are ideal.

You will want to keep at least one mother for future use no matter what. SOG is very efficient, but you need a healthy mother to do it repeatably.

I have only had good success using rapidrooters and dip-n-grow. Don't re-use pots though, unless you have run them through the dishwasher and then sterilized them (microwave, or place over a steam bath in a large pot). In my donkey dick log, there is a whole section on cloning, and also one in the link in my siggy.