I hold out little hope that any good will come of posting here, but I've got to get this off my chest.
THE GAME SHOULD NOT REWARD PLAYERS FOR DOING BORING THINGS.
In particular, I have in mind:
A. Running the same levels over and over, instead of experiencing the full variety the game has on offer
B. Waiting around the elevator for the level to change so, that you can run the same level over and over
It is common knowledge that arenas give far more crowns than most other levels. Maybe there was a point where it was reasonable to believe that most players would fight only the first bout, but it is certainly not reasonable now. Worse, arenas themselves are some of the most monotonous areas in the game.
Players should get comparable rewards on all levels at a given depth. I don't know if those rewards should be what arenas currently give or what other levels do, but they should be on all levels. There are several possible ways this could be accomplished:
1. Include optional challenges of comparable difficulty and rewards on all levels, not just arenas.
I'm sure that'll take some extra design and programming work, but it can't be that hard, at least on the levels that are already randomly-generated out of legos.
2. Put optional challenges behind pay walls that make them comparable to running another regular level
This would probably mean that you'd need to charge energy from all players (not just one, like in danger rooms), and you'd need to offer roughly the same crowns/energy ratio as a regular level.
3. Make optional challenges give only minor or non-cumualtive rewards
Something that most people won't particularly mind missing (at least after they've done it a few times). Possibly vanity items (costumes, achievements, etc.), heat, minerals, quickbar items (vials, etc.), or some kind of token that can only be exchanged for items that are not worth selling to other players.
4. Balance levels on the assumption that all optional challenges are completed
It's probably not a serious problem if someone can accept LESS money than normal in order to finish the level quicker/easier, as long as someone intent on maximizing their income is willing to accept any level.
5. Make optional challenges RIDICULOUSLY hard
Hard enough that the clear majority of players are unable to complete them without spending so much energy on revives that they're not worth it. You run the servers, so you should collect statistics on how many players choose to try them and how well they do and rebalance them if this is not true.
That seems rather inconvenient, since it locks out most players from experiencing that content, and people who DO want to do them will generally not be able to play with pick-up groups. This option would not be my preference. But if you desperately want these to reward players for being awesome, that's how it should work.
And on a related note, the current system of waiving the cost for tier 2/3 entrance for completing the previous tier of the same gate really only helps players who pick a single gate and run it a huge number of times, which, again, punishes players for trying out the full variety on offer. A slightly better system would be to waive the fee for players who have completed the SAME tier on the PREVIOUS gate, so that you avoid fees by playing every gate in order rather than cherry-picking only the best ones.
+1. Good suggestions.