82 1100 Spectre allen wrench questions...

What size of allen wrench do I need for the bolt circled

Not sure of the size. 5mm maybe?

Why not just go buy a package of metric allen wrenches? Get both the type for a socket wrench and the standard L shaped type. A man can't have too many tools.

The parts diagram should have the bolt size, so from that you can probably figure out what size wrench you'd need. Partzilla may even have a photo of the bolt. For stuff like this I would get quality allen wrenches as cheap chinese tools can twist or break & also damage the bolt head. I would also spray some Liquid Wrench & let it soak overnight.

For some stuff such as the bottom allen bolts on the forks you should get a hardened or brake caliper socket. not sure how tight or stuck those bolts would be. not sure exactly what I'm looking at. obviously something to do with the drive shaft.

It could be a 6 vor 8 mm allen bolt. i would buy a set of 1 - 12 mm metric allen wrench.

Why does it seem that they sell many metric allan sets and the 7mm is not included?

It's a size that is not generally needed, get yourself good quality ones and you will keep them all your life.