7'11" is basically 8', which I would not consider "short" in the sense that most people mean when they talk about "short fly rods". After casting a ton of rods, my cut-off for "short and feels somewhat weird when casting" is anything below 7'6".
If you think you'd like to try a 9 weight for LMB, etc. go for it brother! Just because loads of folks online only seem to talk about 9' 8-weights for that use means doesn't mean that you won't prefer something different. If you want to fish for smallmouth with massive poppers or streamers, bring your 9-weight for that too and just don't talk about it online afterward...I bet you do just fine ;).
For leaders for floating line, I make my own tapered leaders in a manner similar to how Rob Snowhite does his, with length based upon the fly size/weight, and wind. That said, I rarely fish a leader longer than 7' for warm water anymore, and often cut off down to 6'. If you're using heavier tippet (like 12-15 pound mono versus 1-3x or something), the taper becomes somewhat less critical in my experience.
I own sink tips (10' fast sink tip + floating running line), streamer tips (4' fast sink tip), teeny shooting heads (20-30' fast sink + floating running line), and orvis DC lines (30' fast sink head + int. running line), but I use them so seldom around here that I could set them all on fire and never replace them and still die happy.
For sink tips, if you're fishing a leader longer than 4', you might as well just fish a floating line and weighted fly in my opinion (unless you like "sag" and poor feel under the water).
If you're worried about pulling large fish from weeds with a 9' 7-weight, those must be some real weeds. Just point the rod at the fish and remove "rod" from the equation, and you'll horse them in....at the expense of putting more on your tippet, and more hook pull-outs. You could just use a 5-6' rod and really give yourself some power, but then you have to deal with casting a 5-6' rod all day......
All opinion ^^
TB