1. Get 12 word seed from Mycelium
2. In Electrum... "File -> New/Restore -> Standard Wallet -> I already have a seed -> click 'Options' -> Check "BIP39 Seed" -> Enter 12 word seed from Mycelium -> Leave Derivation Path as m/44'/0'/0'/0"
Wait for Electrum to sync up... it should show your transaction history and balance pretty quickly (seconds), but your transactions will probably show as "Not Verified" until it has fully downloaded the blockheaders... might take a minute or two... if you select "Tools -> Network", you should see the "blocks" number counting up... once it reaches the height of the Blockchain, currently around 481,100 or so, it is fully synced...
NOTE: I'd probably recommend that you setup a completely new wallet in Mycelium with a new seed etc. before you send the coins back... by importing your seed to Electrum you are potentially exposing it.
Hard to say what is going to happen with transaction fees to be honest... keep an eye on this:
https://blockchain.info/charts/mempool-count and
https://btc.com/stats/unconfirmed-txWhen the mempool count is low (10K-15K or less), you should find that the fees come back down... in any case, as long as you use a fee that is higher than 10 sats/byte, you'll be able to use the ViaBTC TX accelerator... it can be hard to get one of the limited slots tho... and even when you do it can still take up to 12 hours for them to find a block. So you need to be aware that all your coins could be "stuck" for a while if you attempt this.
Thank you very much for your useful information, I will do it as soon as I can.
While I will continue to receive small transaction amount (from faucet or small investment) I think I will be in the same situation after few month.
Can I do the same process once every couple of month?
Do you have a android wallet (better if sync with desktop) that are not creating so many byte for receiving all the "dust" that I will continue to receive and has manual transaction fee option?
Thanks again for your help