I weight all of 165 and don't feel the bike is sluggish. There are bikes that feel quicker though.
It is my main ride though and i like it. It seems to get quicker as I ride it more, and slower when I slack off and not ride much. Something tells me that isn't the bike's fault. Generally speaking, as far as the weight of a tire, or other component goes, the rider's weight is usually the biggest factor, so knocking off a alf a pound here or there on the bike won't matter much.
Your questions regarding geometry do matter of course in how a bike handles and in quickness to a point. For an all around ride I like my LHT and you probably would too. If you have the chance to ride one before buying that would be great. It is a strong frame so it should suit your needs well, although I am sure there are others that would as well.
The long chainstays are great if you want to add bags.
Have you looked at a Cross Check? They have shorter chainstays. I believe the frame is a strong as LHT, but I may be wrong. I went on Surly's website and looked at both but I'm not completely familiar with the Crosscheck. The frame tubing may not be as thick as the LHT though. It is very popular though and has a bit more sporty geometry compared to the LHT.
No matter what you get, just make sure it fits you and you like it.
Phil