The avatar is the user’s Trimble account avatar. You may not believe it, but currently you have to go to 3D Warehouse → User menu→ Edit Profile→ Change Picture (click on the avatar).
If you want your professional store not to use the same avatar as your 3D Warehouse models (maybe personal account), it makes more sense to have different accounts/identities for professional (or company) and personal. If this is important you could have to contact the EWH team directly to see whether it is possible to transfer content to a new account.
I thought they had contacted developers in advance, so they can make adjustments.
For not overwhelming users, the description is designed to be now more like a concise, focussed promotion text. It seems the limit is 1500 characters. Also, the summary text (1 line) is what is displayed in the search results and must fit in the limited space. In my summaries, I removed verbs and redundant words that are clear from the context.
So you could for example change:
“Cut list and cutting diagram generator from Sketchup model” → “Generate cut lists and diagrams”