I live about 3 miles east of downtown Charlotte, NC.   I am in an old neighborhood with lots of trees.  There are two channes within 10 miles that I do not receive well.  These are CBS (3-1, freq. 23) and ABC (9-1, freq 34).  The CBS tower is west northwest of my house and ABC is East Northeast of my house.   I receive other channels in the same directions which are farther away.  Below is a link to the TV Fool report for my location.  My antenna is approximately 20 feet high.  I only have 1 TV attached to the antenna 
http://www.tvfool.com/?option=com_wr...60b507c76cdbe7
I currently have an AntennasDirect Clearstream1 mounted to my chimney above my single story house pointed North.  I have approximately 40feet of old cheap cable connecting the antenna to my TV
Questions are:
1.  I do not have the metal reflector installed.  Would this help and what does it do?  I did not notice a difference when I tried it with the deflector inside of my house so I left it off.
2.  Would buying a larger antenna help?  I was thinking about the clearstream 2 antenna.  This has a 50 mile radius and a gain of 10.2dbi.  My current antenna (Clearstream 1) has a range of 30 miles and a gain of 8dbi.  
3.  Would a pre-amp help?
4.  Is it possible to connect two antennas pointed in opposite directions and then run one cable to the TV?