Just wanted to make sure this was a relativeyly safe configutation

I consider myself a relative safe surfer - no p2p, only visit a few trusted sites mostly, and dont do the file sharing thing either. So it is on this basis that I decided to use the trusted vendors list.

I added the following vendors to the list, and I was just wondering whether there was any reason not to add them. That is to say, I don’t want endless popups from Defence + for everyday activities, instead only when a new untrusted vendor comes along - eg installing a program from some devleloper I have never heard of.

So what I am asking is could someone please look at the list and see if thats okay (I was unsure of whether to add Opera to the list as thats my browser…).

I run Comodo 3.5.54375.427 (or something like that - woudl be much easier if I could actually copy the About information, rather than just the hash :D), its in Clean PC mode. Firewall security set to safe mode.

Comodo CA Limited - Default setting.
Comodo CP inc - Default Setting
Microsoft Windows - Deals with lots of the Windows Updates, making it totally automated.
Yahoo Inc. - Yahoo Messenger
Avira GMBH - Avira Antivirus.
Javacool software LLC - Spywareblaster
Piriform Ltd - CCleaner
Sun Microsystems GMBH - For Java and was meant to be for Open Office but some of the python coding (inbuilt add on to Openoffice is not signed alas.)
VMware Inc - Vmware player and converter.
Google Inc - Google earth, google talk and google chrome.
Microsoft Corporation - Deals with other updates, such as Silverlight, NET Framework etc.
Opera Software ASA - Opera browser.

Is it okay to run it like that? I guess what I am asking, is there is not much chance of the digiital signatures being copied or faked by someone. And the fact that I am running like that, given that those vendors are all reputable and relatively trustworthy (if you leave aside the dodginess of Yahoo toolbar and Google’s privacy invasions :D), it should be relatively safe to leave those in my trusted vendors, right?