I was about to invest and I read this:
"Are you sending from a Counterparty compatible bitcoin wallet?"
I wasn't sure about it (i'm using Trezor) so I came here and read that I can't send using Trezor. Which wallet can I use?
I used Trezor to buy 50,000 XFCCOIN without reading the guidelines. I sent 0.57120244 BTC and received 0.0000543. Did I loose my XFCCOINs ?
You didn't loose them.
You can put your Trezor public address in here:
https://counterpartychain.io/address/and you will see that you hold 50,000 XFCCOIN.
Getting the XFCCOIN out of there is another problem as Trezor doesn't yet support Counterparty assets. This is something that only Trezor can solve.