EEA Surinder Singh Route with UK based employer?

[Lolabora]

I currently work for a British company in London and my employer is sending me for a few months (5 months) to France to rebase there and take care of customers in the EU, however I will continue being paid in the UK. I just got married and we are dealing with this whole drama of living together with my non-EEA spouse in the UK. I need to know if I can make use of the Surinder Singh route to bring my spouse into the UK once my employer requires me back in London permanently.

The regulations or interpretation for Surinder singh have changed recently and I'd like to know also if:
1) I can use it by just residing in a country within EEA, e.g. being paid in UK but living in France, (example: people who are pensioners from UK but live in Spain, etc., don't they have the right to return with their spouses to the UK if they are self-sufficient?)
2) If 1) isn't possible, shall I work as a self-employed invoicing my employer and declaring that income in France? or,
3) Continue being paid in the UK but asking my employer to pay me in my new French bank account declaring this income and paying the corresponding taxes in France?
4) My employer has a branch in Monaco, and I may be sent there. I can still live in France near Monaco, so within EEA, and being paid in Monaco too. Is this fine for Surinder Singh?

My employer can accommodate things in order to make them compatible with the purposes in my current personal life so to relocate with my spouse in UK if needed, however I need advise on how my situation can be best dealt with since the very beginning and I would thank you for any clarification as to how to organise this better.

Thanks! Lola