What issues do you have with IB? I have all my family accounts at IB. They have key account services for people doing $400 a week in commission so you get priority support.
Have you thought about going to HSBC or UBS? You can open an international Schwab account at www.schwab.co.uk or from Spain https://international.schwab.com/ This may be a way to get think or swim internationally in 18 months.
In the U.K. people spreadbet and trade contracts for differences CFD. This may develop in Nevada or other territory where betting is legal to get around the tax.
There is 0.5% stamp duty on Shares traded on the LSE and you are complaining about 0.2%!
EDIT: foreign companies are exempt if they do not have a share register in the U.K.
https://www.londonstockexchange.com/trade/stamp-duty-exemption?lang=en
Zero hedge banged the drum for bitcoin at $300. I would call that good financial advice. The trouble the people who criticise conspiracy theories (a phrase invented by the CIA) have is that some of them turn out to be true e.g the massive JP Morgan short silver position.
You could get a second monitor so that you have tos and IB TWS mosaic on separate screens so no need to alt tab. Have you looked at www.scanz.com and www.tc2000.com ?