I use a paper towel to get a tap root for a few reason. The biggest being not wasting time and space on duds. I pop bagseeds for now and they dont all pop.
Look into low stress transplanting. its not any more stressful then taking the plant out the pot to look at the roots.
I prefer to pot up a few times but you can easily start in 1 gallons. I did my first grow.
wise words indeed CFL
I don't like wasting time, space and resources on a seed that won't make it.
space under the lights are valuable real estate unless your doing small numbers.
when potting up, if your doing numbers its the most efficient way to go.
look how professional nursery do it for numbers.
as far as stress goes, unless your like a rabid bull in a china shop transplant shock shouldn't be an issue anymore than checking the roots as CFL said above
same goes with handling seeds with a tap root on them.
in fact mine seem to look better the next day when I up pot and the roots start growing out into their bigger home.