Ubuntu :: Delete Programs That Are Under The Applications Tab?

I'm extremely new to linux I've been a mac user for 6 years but recently purchased a new laptop that has windows 7 and immediately made the switch to ubuntu 10.04 after reading very good things. Problem is I like what I see very much but have no idea what the heck I'm doing and have ran into some problems.

1 How do you delete programs that are under the applications tab? I ask this because I downloaded songbird but my 32 bit system cannot open it so its there but cannot be used. Also how do you delete programs in general that you wont need?

2 How do I go about downloading songbird for the 32 bit OS?

3 I have tried to download the cpu vista meter but don't know how to install it once I have the files to extract.

4 When I boot up this machine I have the option to start up 4 different ubuntu OS' Ubuntu 2.6.32.22 and 2.6.32.21 plus their recovery modes. Question is did I screw something up during the partition and if not what is the difference between them and do I need both.

5 is there any way to access options regarding the sensitivity of the mouse pad it seems to be only for a hand held mouse

6 is there anyway to change the sounds played by empathy when messages are sent? are there any alternatives better than empathy?

7 I never partitioned a HDD before and was wondering if it was a good idea to set equal amounts of memory for windows and ubuntu. Also whats a safe way of giving more memory to a partition or removing a partition all together?

Thats it for now. I've ran commands through the terminal to get the cairo dock and that worked fine along with a few other apps.