You seem to be confused about what you want to do.
Picasa is a Photosharing site as well as a photo editing system.
Irfanview is a Photo editing program
Photology is as far as I can see a program that is for organizing your pictures, similar to Picasa.
If you change whatever program you are using to edit your pictures you will need to associate the pictures with the new program, any editing that you have already done will not change.
To be safe it would be a good idea to archive your pictures onto CD/DVD or external Hard drive. I would not like to trust all my pictures to an online archive.