To address your concerns more specifically:
Brightness - the forum's colour palette is the same it's always been. Only difference is that we now have a solid red bar at the top of the page to fit in with the rest of the website.
Squashed avatars - No, they're not squashed. That is the image you uploaded and now it's presented in the correct aspect ratio. If you want it to be square, use an image editor to make it square and re-upload it (
http://apps.pixlr.com/editor/)
Wishy washy colours - Again, we are using the exact colour palette we used pre-update. The colours are all the same.
Advertisements - The advertising has been there since 23rd December 2013.
The New Posts is the same as Recent Posts, just different wording
Unfortunately, we had to remove Watched Threads from the top bar as it was causing a couple of conflicts elsewhere on the index. Hopefully we'll have this fixed very soon.
Ah, I see. Basically, the TapaTalk (the framework we use to build the app) forced us to throw in Sponsored messages in order for it to be approved in the app store. We didn't want to do this as we felt it somewhat spoiled the app experience, but didn't really have a choice.
Personally, I prefer to just use my browser if I want to access the forum on the go. The site is designed to shift its contents around based on the device's screen size so it'll work perfectly on pretty much any mobile device