I have two suggestions.
1. Allow partial investment of SE to improve Abilities and Skills. Currently if a player has some SE they can use it for building, which reduces the cost of improving luck incrementally. If it costs 150,000 SE for example to improve an ability why not allow a player to invest a little at a time as opposed to the entire 150k all at once? The same modification could also be made for investing in skills, although they are generally much cheaper than abilities. This would help out the weaker players significantly and level the playing field in some cases.
2. Enable a feature to sell multiple items at a time, e.g. with the burned out relics it would be much easier to sell 10 at a time (just like buying the potions from the huckster). It would also help to be able to sell multiple items in the auction house, e.g. 17 froglok rings at a time.