Louise, if your Hubs are being unFeatured when they're edited, it has nothing to do with quality - it just means something in them is against the new rules.
Old Hubs aren't checked for compliance with the new rules - HubPages doesn't have enough manpower to do it. So if you've got Hubs that have been published for a while, they may be breaking the rules and you don't realise. When you edit an old Hub, that's when it gets checked.
I have a Hub about The Basic Rules - you'll find it on the slider on my profile. It covers all the rules you need to follow. I suggest you read it carefully and see if you can understand what the problem is. If you still can't see, try posting some of your Hubs in the "Improving Your Article" section of the forums and we'll help you.
Looking at your Hubs, my initial reaction is that you seem to be blogging, rather than writing magazine-style, stand-alone articles (which is what HubPages wants). If all your articles are on a theme of Limitlessness, you might be better off starting your own blog with that as its title and moving your Hubs there, rather than publishing individual articles on HubPages.