There's a relatively easy way to prevent people from inviting someone to their guild, doing a tax-free trade, and kicking them or having them quit the guild. Use the same system that prevents brand new members from their CQ being eligible towards the guild count -- they've gotta be in the guild through a weekly reset else the transaction gets taxed. Sure, guilds might get taxed a bit for brand new members but it would mitigate that problem.

I understand the need to manage certain secure trade and in-game mail transactions that are being used as loopholes around the GTN fees. Such is, without a doubt, disruptive to the game's economy. There should be an exception for members of the same guild. This will help ensure the game is not inadvertently "taxing" normal, routine guild transactions. Many guilds reward members with credits, gear, and other items for various activities. Prizes may be mailed to guild members or provided via secure trades. These transactions should not be subject to fees. Another option to help manage the economy would be to add a scalable "luxury tax" on the GTN+ transaction fees. Maintain 8% up to 250 million credits and scale up to ~20% at 1 billion credits. This would help discourage price inflation for high-value items.

I'm a returning subscriber. I picked up a Nexu creature companion and absolutely love her! The Trick: Preen and Trick: Play Dead are nice additions; alas, they're a pain to use since you have to open Abilities -> Companion to get to them and they will not bind to a quickbar. Could they be bindable or placed on the companion QB for easier access?