I do agree that professional advice is required. You can contact me privately for a list.
A few points, if I may.
1. Bear in mind when you are looking at your best option, that if you draw the whole pension it will be taxed as income in France.
2. When we last looked at the UK French treaty we came to the conclusion that the 25% lump sum in the UK would be taxed in France at 7%, but rates will now be different.
3. One assumes you are actually old enough to draw upon your UK pension.
4. One questions too whether the tactic helps your final goal (which might be net spend for life). If you have low income in France apart from this pension, you may want to run the numbers for taking the UK pension slowly and using up your French allowances. The planning work should start with a statement of what you are trying to optimise.
5. I am still uncertain, I'm a little abashed to say whether the Lifetime Allowance charge is covered by the UK French Treaty. At the moment, I'm guessing not, since it seems to me not to fit happily into any Article. If asked, I'd want to do more research. The question may be moot anyway since the sum you have in mind may be covered by the LTA.
6. When it comes to death benefits, start with the Estate Duty DTT https://www.legislation.gov.uk/uksi/1963/1319/schedule/made and work through that. There are eight different ways to pay death benefits from a drawdown, so since an answer would be long, permit me to give you a likely bottom line - the gift should be taxable in France, one can't analyse the likely tax in France without knowing the whole estate and who inherits what, but broadly, if you were going to leave the pension intact in the UK you might consider leaving it to a trust or specific beneficiaries to get the result you want. Each case requires an individual model to be constructed if one wants optimal results. There are no short cuts when it comes to non-resident tax planning.