Installing Comodo Firewall and general security guidance

Firstly please forgive my lack of knowledge in connection with PC's. I am fairly OK using my PC but not to sure when it comes to the security and optimization side of things.

I have read a few threads on security and decided to install Comodo Firewall. On install it asks two questions as follows which despite further reading I am none the wiser :

1. Do you want to change DNS settings to Comodo secureDNS

2. Do you want to enable cloud based bahaviour analysis by submitting them to Comodo.


Can anyone please advise whether to accept one,both or none at all.

My general set up consits of Avast free edition anti virus software with settings "on" and I also have the free editions of Superantispyware and Spybot, both of which are used for scanning on demand. I am not sure if I need both or whether one of the two is OK or whether Spywareblaster maybe a better alternative.

I am also looking at installing Sandiebox, another program which seems to get good reviews on the forum.

Finally, is there any recommended optimization program, free preferably, which I can use to keep my pc running smoothly. I do have CCleaner by the way but a couple of programs I have seen (Winoptimizer, Amigo 360) look as though they have more features

Any help would be appreciated.

Many Thanks

Andy

1-surf from a LUA / SUA
2-UAC on max
3-Sandboxie
4-add whatever A/V you want, it wont matter which because you have sandboxie which is 99% of your security
5- use windows firewall, its more than enough protection.