I can answer part of your questions. It is quite true that disturbing the bulbs will disrupt bloom for a minimum of one year, maybe more, depending on the size of the bulbs. Crinums are tough and grow in a wide range of conditions, but they definitely appreciate good drainage, regular moisture, and fertilizer. I grow mine in the ground and have the best blooms with a fall dressing of composted manure around the bulbs. I also mulch them year round.

Ellen Bosanquet is a beautiful, deep rose crinum that offsets rapidly. This is why it is so easy to find commercially. For me, its drawback is it only blooms once a year, whereas many other crinums bloom continuously for several months each year.
Elizabeth Traub has the same bloom color as Ellen but blooms from early summer till fall for me here.It does offset, but not quickly. I got my original bulbs from a seller on Ebay.

I have not grown crinums in pots for any amount of time, so cannot help you with those questions.