If you use Raid for other drives on your system you should leave it on Raid if not you can switch it to AHCI. It is best to do it when you do a clean install of Windows 7 otherwise you have to edit the Registry.
Having your page file and hibernate on your SSD should not have a impact on performance but you lose a lot of space and the system is doing more writes to your SSD wich affects drive life. Some people switch their page file to another drive but if this is a mechanical drive it will actually be slower.
Most of the time you won't need a pagefile as big as windows allocates and a lot of people make it smaller, this only will gain you some more drive space. Here is a Link to the Corsair Forum with tweaks you could perform to make your pagefile smaller and lessen the writes to the disk: Windows 7 Tips & Tweaks - The Corsair Support Forums
Remember those are tweaks and not all of them will be necessary and are at your own risk.
I first would see if Garbage Collect will recover some speed before I would do a secure erase and clean install.
Did you see my advice I added on Defrag in my last post?