Several vB questions for new licensed user

[Tanapangarap]

Hi, my searches weren't so fruitful for some of my inquiries, so I thought I might ask them here:

1. I added a custom favicon to my forum. It appears before the domain, on the address bar, but it hasn't appeared on my bookmark on Firefox, despite re-adding. Need I simply clear my cache?

2. How does one change the default vB welcome message on the index?

3. Is there an included feature, or a modification, that allows for certain, chosen forums to have a time limit for editing posts (the exact time of which can be set by the admin), or for getting rid of editing in those forums altogether?

4. How does one display on the view profile page what percentage of the total post count one's posts make up, like on phpBB2? Or how can I find out what percentage of the total post count my posts make up?