I know it takes tiny sub-penny amounts as transaction tip for devs, but I think it took like 30 some dollars worth of BTC.
No, that is the transaction fee, which is paid to the miner that includes your transaction in a block. It is an incentive for the miners to include the transaction so that it confirms faster.
First of all, what you linked to are not transactions but addresses. They are different, but in this case, it doesn't really matter.
What I see is that you are confused by the change addresses. It is bad practice to follow your balance on any block explorer due to change addresses. What most wallets do is that for each transaction the change is sent to another address generated by the wallet which is still in the wallet and still in your control. This is to prevent address reuse which is generally not recommended. So the Bitcoin that you see in blockchain.info going to another address is most likely the change. And the balance you saw in your wallet was correct since it included the change. And the change and whatever was left in that address was sent to mycelium when you emptied the wallet.
As you can see in this transaction:
https://blockchain.info/tx/c708e9d51ddd78b55e71e3fe7d5d352d3c7815eedfd2098348df49d26376f313, the three addresses you are concerned about, yours, and two change addresses, are all apart of that transaction which is sending all of the bitcoin to another address, your mycelium. This means that the same person (you) owns the three private keys for those three addresses, so those two extra addresses you don't recognize are your change.