try the SigHosting hack for the last 3... so your requests are fullfilled for free... btw, that hack is for external uses of the image url, but i plan myself to have a different version of that hack to simply upload and manage them as the actual system, instead of a different image..
Well actually I think that would take care of all 5. Since it appears that it only allows 1 sig image (#4), and I'm certain my members would prefer uploading to my site than Geocities (#5). What exactly would your personal changes do from the original?