"One thing I'm not clear about, though, is if I didn't want a yearly "contract", is that possible? Can I just pay per month and then cancel when I feel like it without a penalty?" "If I'm paying by the month and find any info I was looking for in, say, 9 months - can I just write to Ancestry.com and ask them to cancel me?"
No. That would be a month-to-month "contract", and there isn't one.
"One last thing - is there another program similar to GEDCOM? I found out there are no updates for it (per their site)." "I was told that "the programmer who did Gedcom has retired" or left the company - something like that.. and they were not going to do any updating."
Don't know where you were, but there is no "gedcom site". Where were you, really?