I have no problems with this on my XP Pro system. I have set the firewall to treat Ashwebsv.exe as web browser and I get no slowdowns at all.
With regard to the connections taking a while to disappear, I noticed this too but when I checked with TCP viewer from sysinternals it showed the same connections as ‘Time wait’ or ‘last action’. I think the way the firewall shows traffic is a little different to tcp viewer, perhaps there is some delay in its display of changes. I would not worry about this.
Perhaps your slowdown is due to something else - are there a lot of blocked events in your firewall logs?
I am also using 22.214.171.1246 and Avast! with no significant slowdown. Do you have any of the items under Comodo Firewall attack detection settings/miscellaneous checked? These can add significant overhead to web browsing.
As for what is going on with the connections:
An http request to a website will create multiple TCP connections to download the various “pieces” of the page (pictures, text boxes, frames, …) in parallel, as well as connections for the referenced sites on the page (ads, more pictures, …). The connections are persistent, with timeouts set by the server, so you are not constantly churning connections to refresh the same page. Ashwebsv also “listens” on port 12080 (proxy port) in case a new http request comes in from your browser. Since all of your browser traffic goes through Ashwebsv (except for https on port 443), it is handling most of the direct internet traffic. You will also see Ashmaisv go up and down if you are using a mail checker, otherwise only if you are using your email client. Other processes will “listen”, but generally for local (LAN) traffic that occurs only occasionally.