I have a Seniorita which you probably already know is the smaller version of the Senior.

Like mentioned above, make sure you add ailerons. This is a must. If I was doing it again I would probably add some big 2" barn door ailerons, and probably flaps, but the flaps are optional for you.

Take out a lot of the dihedral. You can get away with taking it all out, but I would leave maybe a 1/2" just so the plane looks good sitting on the ground. Trust me on this one, the plane will be much funner like this. My Seniorita has the recommended amount, and while it's a very gentle plane, it does real sloppy rolls, and any other maneuver really isn't possible because it constantly wants to correct itself (not a bad thing, but not very fun if your an experienced flyer.)

One option that I'm not sure would work, but I'm going to try someday is clipping the wing by one rib on each side. These planes float like a glider, so I'm pretty sure it would work. In fact it would probably be better because I almost have a tough time landing mine because it just keeps floating and floating, and floating until I've ran out of runway.

I would imagine that a Senior could handle a .91 stroke just fine. My Seniorita is rated from a .15-.25 and I have a .40LA on it right now. It's much funner with the extra power, and I think you'll enjoy yours too if it's overpowered.

The suggestion about the wing bolts is right on. As long as your not landing real rough it like a lot of beginners do, you'll be just fine with wing bolts. Plus it looks a lot cleaner.

A also agree with making it a tail dragger, and flying wires. I wish mine had them. It would look real sharp if you put wheel pants on it too.

If you have any other question let me know. I think you'll enjoy your Senior. It's a smooth flying plane, and with the right mods can be as wild or mild as you like it.