CSS Menu Writer is a very flexible products and it allows you to customize a lot of settings. some of these settings are Advanced Feature for Browsers such as IE 6, which is why we include a separate style sheet for IE 6. This way you are able to make changes specific to IE 6. Looking at your menu in IE 6, I don't see the issue with the full width or the hover state not working, please see attached image.
In regard to your PowerSore comments, each version of PowerStore have a list features that were added in each release. After Powerstore v2, added options, more gateways, more shipping providers, ...
And with the release of PowerStore v3, we added, CMS, installer, user managements, coupons, sub categories and the list goes on.
So you could see that with each release we are trying to add features that users are asking for and that would help them in developing sites.