Thanks Tim and timgr for the replies.
A few notes to add:
I have connected a TV directly at the point of the splitter and had very good reception, however, as I mentioned in my initial post, sometimes the reception on all of the TVs is pretty good so what I haven't done here is to wait until a time when the main tvs are having issues with a certain channel and then go down and try the direct connect tv test. There is a chance for some weather to move in this weekend and if I notice the connection issues I will try and perform this testing and report on the results.
A signal amplifier was mentioned. An 8 channel distribution amp would also allow me to wire up the remaining rooms pretty easily. Are there any recommended units to look for or will a basic unit like this work?
http://www.amazon.com/Channel-Master.../dp/B002M1EPL0
As far as the external mounting for the antenna, that is a possibility. About 10 linear feet away from the attic mount location on the outside of the house is the old directv dish still mounted with a coax line running from it into the basement where the junction is. That would be the location for where I would mount the antenna outside, and I would probably use the same mount and just remove the dish and rig up the antenna to the dish mount.
Also - one more note, it was mentioned to rig up a dipole kit for the WHAS signal - I am assuming that this is due to it being a VHF signal. The interesting thing is that I have never noticed any issues with that station. The two that I have noticed issues with are the WDRB and WLKY stations (both UHF). Not sure if this adds much to this conversation but thought I would mention it anyways.