The PTS provides templates for building max-level characters, but these templates lack things that a normal progression character would usually have. Some of these are immediately obvious, while others are more subtle. Below are a few of the things that are missing, or need improvement. Please add your list of problems, and suggest possible solutions, don't just complain..
1. All those nested containers in your inventory.
2. No Companions.
3. No wayshrines
As a possible solution to the containers and wayshrines. There could be a separate PTS vendors realm. This realm would only exist on the PTS, and would be accessible from any wayshrine. It could be as simple as a large room, with vendors scattered about. The vendors could operate the same as a guild vendor (and actually be a guild), but each vendor would specialize only in specific stuff (heavy armor, light armor, medium armor, books, 2H weapons, staffs, 1H weapons, furnishings, crafting materials, companion gear, etc.). Every new character created on the PTS could automatically be enrolled in the vendor's guild. If all PTS users are in the vendor's guild, the issue of no wayshrines is also solved, as "travel to player" would be available. All of the items that are currently loaded into those nested containers could be freely available, in unlimited quantities, and the characters get their bags and banks back. Additionally, using vendors, instead of nested containers, will allow all of these items to be listed directly, making them text searchable.
There is no other solution: All of the companions should be unlocked, and they should all be at max level.
Please note that these observations pertain to only the max level template characters, but all toons created on the PTS should be in the "PTS Vendor's Guild" , and should have access to the PTS vendor's realm.