It is certainly great. Here come my list of suggestions:

1) Not log in bit, if you are already logged in then should skip those log in bits
2) on the front there should be a system that says "6 of your saved topics has new replies" or something like that
3) How you going to order the saved topics?
4) Make it into pop-up so a little box comes up with your saved topics.
5) templates would of course be good.
6) no sure what you have done to "5 links" but the pages with the saved threads on them do not have the yellow folder images
7) Sort the saved threads under categories so it does:

Category Group > Category
Thread 1
Thread 2
Thread 3
Category Group > Category 2
Thread 4
Thread 5

8) Make the thread number input thing a hidden field. No point showing that to the vistors, it will only confuse them

Well just some ideas anyway, take what you want from it.