1) Yes you can add odd numbers of T1s to a multilink bundle. I think the max you can put in one bundle is 16, but I can't remember. I know it is at least 8.
2) Yes you can, it doesn't matter which interface card they are on.
Watch out for 12.4.22T. I had three multilink bundles on one 3825. Two of the three bundles would not hold a T1 member for more than 20 minutes. TAC said to upgrade to 12.4.24T. This worked. They are now stable.