Link to picture:
http://hortiplex.gardenweb.com/plants/jour/p/27/gw1085827/page.html?12079

Click on the small dot above the word Elephant and you will get my pic.

Thanks,
Rick

I'm no expert, but I hope this helps...

1. Yes, trim the roots - and wash off all the dirt.

2. Save the old corm that is detached, it may produce another plant. It would probably be a good idea to put Rooting hormone on the new corm where it was attached. The hormone has a fungicide which could prevent rot from starting at that point. Leave the others attached.

3. From your photo, it looks like you have cut them about as short as needed. The petiole stubs will dry up, one by one, and you can remove them as they do.

4 Yes, that is what you plant next year.

Very difficult to tell what you are growing from the photo of the tubers Rick but it is likely Colocasia esculenta. This is the most commonly grown form of "elephant ear.

Despite common misconceptions, you do not have a bulb or a corm, your plant is growing from a tuber since all the roots grow from the top. Read the link below and it will tell you the differences. All aroids grow from tubers, not corms or bulbs.

Your plant could also be a Xanthosoma or one of several other genera. Look at this link and hopefully you can tell the difference. Tubers, bulbs and corms all all very different physically despite the fact they are all starch storage units and underground stems.

http://www.exoticrainforest.com/Colocasia%20esculenta%20large%20pc.html

There are hundreds of leaf forms to this species due to natural variation.

Sounds like you did it right.

Steve

Here is a link that might be useful: bulbs, corms, tubers, stems, etc