Any technical aspects I should know about in choosing the proper tip weight for my arrows?

Here are my arrow specs:

27" 7595 Gold Tips
5" Shield Cut Feathers

I currently have 75 grain and 100 grain heads to try out. I haven't received the fletching yet, so I can't comment on flight except for some old aluminum arrows I put through it. Should I go with a heavier head given my feather size, or stay with the 75 grain Muzzy's for hunting?

Also, how close to the back of the arrow does the back of your fletching come? I would think that as far back as it can go would be the right thing to do, but I never see this configuration and was wondering why.

Thanks,

Fritz