I wish to ask a few of questions (and maybe make a couple of suggestions) about using multiple keys and change addresses.

• First, am i correct in understanding that if you are using a single address and private key whether it be generated by Mycelium or imported from elsewhere that change is always returned to the same address?
• Also, am I correct in understanding if you have balances in multiple active addresses and you wish to send funds totaling more than is contained in any single address, that multiple keys will be used as inputs for the transaction?  If so, where does the change go? I am guessing that it goes to one of the active addresses used for the transaction. If this is the case, I might suggest it would be better if change were by default returned to an unused active address if available.
• Since only one address can be associated with your Local Trader account, am I correct to assume change from a trade is always returned to that one address?  Is it possible to transfer your trader profile and reputation to another address?  Also, since you can only post ads if you have the balance available, does that balance need to be contained entirely in your trader address or is the trader app able to use balances from all active addresses?  It seems it would be safer if it were the latter. That way you could avoid reusing addresses.

The reason I ask is that if my assumptions are true it seems possible that by deleting all keys generated by Mycelium, creating a deterministic wallet in Armory, generating several private keys, then importing those into Mycelium via QR codes, you can essentially keep your Mycelium wallet synced with Armory while also avoiding many of the pitfalls of reusing addresses, especially if my suggestion on the second question were implemented.  The only minor hassles would be that you would have to remember to archive and\or delete used addresses in Mycelium and be sure to keep enough unused keys available.  These of course would be more problematic if you make a many transactions.  Some sort of indicator next to the key informing you of the number of transactions associated to that address would make this easier.  What would really rock would be to have the ability to share one or more deterministic wallets with Armory, though I fully do not expect to see that in the immediate future if ever.

VARIOUS EDITS:  Clarifying my ideas, better wording and grammar because I always just post my first draft

LAST EDIT ON A COMPLETELY DIFFERENT TOPIC:  I really like seeing my balance and transactions displayed in µBTC.  Even though I was an early convert to the idea of bits, I was quite surprised at how easy the mental adjustment actually is, especially with the grouping you used on your display (i.e. spaces instead of commas, no decimal... for now).    I'm on the fence about displaying µBTC vs bits.  While I believe the optimal solution would be to use formal notation in wallets while pronouncing them bits in conversation, this might cause confusion for novice users.  My thoughts on this are different than most.  If it were my choice, I would display bits by default to encourage adoption, but make µBTC an option and transition to using it as the default once bit was solidly established and understood to represent 1 µBTC (probably at least a couple of years down the road).