Assigning members when creating a group

I installed Subgroups for OG.

Now, when creating a new group, I see a multi-select box to choose who's the member of that group. All users of my test site are pre-selected. Giving the group owner this control may result in:

1. The group owner diselecting itself from the list of members, which results in the group owner not being able to join the group if the group is moderated; and

2. The group owner may make some users members of the group without realizing.

Is there an option somewhere to:

a) make it so group owners are members of their groups by default; and
b) hide the members multi-select box from the "Create group" UI?

Many thanks,
Marcelo.