All those items have been discussed, and while the Developer is the final (and only) vote on the subject, here's the consensus:
1) Inventory space is a regular subject. Currently, the person has the backpack they start with (normal inventory), 4 town hall vaults, 2 houses with chests and some spare chests in the wizard tower. Plus, you can store equipment on unused Companions (annoying to get back, but doable). Some how that's not enough (we like to collect!). Having the Companion have his or her own backpack is a popular request or having the ability to acquire bigger backpacks.
2) The in-game warning about quest items (or certain unique items) *should* be in the current or next update? I think it was greenlighted by the Developer awhile ago. Nothing like selling a quest item for a TownHall quest to ruin your play session
3) Scroll of instant enemy re-spawn: A way to reset enemies without staying at an inn has gotten little traction. Just stay at an inn. Seriously, you work hard. Sip a Friguld rum and rest a bit.
4) Two-way scrolls: This idea didn't get traction either. A two-way scroll would ruin game balance for longer dungeons. Even if the dungeon re-set enemies, it would allow returning to a dungeon at some random midpoint.
5) Destination Choice: This one got traction as the current system of the game's default "closest town" can make for some odd escapes. Also, such scrolls would defeat the purpose of teleport rooms inside wizard towers. Not seeing this one becoming a reality, even through it might become a popular item.