Ehm.. you dont even check the confidentiality of the proxies? Most proxies on those sites listed, will either be bad (not working anymore) og not be anonymous.
For that you need a working proxy judge - thats not always easy to find.
If you want to get cought, then go with what youre doing.. not checking proxies for anonymous or not - thats retarded.
And another thing: You need to adjust your number of bots attacking the site - either you risk its going slow, or all your proxies could be instant banned cause of too many attacking.