Your silver strategy sounds very reasonable.

EI actually does fly to Warsaw for limited days/flights around Christmas. You never know, one or two might suit. You will probably do 99% of your travel on FR if you want a direct option.

In general EI is good with cabin baggage however if you end up flying on Emerald the overhead bins are much smaller and you may have issues. Link here to info: https://www.aerlingus.com/prepare/ba...ry-on-baggage/

I was flying back from LHR recently and my bag was weighed at the gate “because it was a full flight” and checked despite being AerSpace (because I had stuffed my personal item into my roll aboard for speedy boarding and wasn’t given any opportunity to explain that or remove anything from it, including my passport, keys wallet etc. Long story short EI have issued an apology and voucher).

However in 20+ EI flights in the last 12 months and dozens more over previous years this is the first time I’ve had or seen any issue with cabin baggage. In general I would suggest on the a320/a321 you shouldn’t have an issue with weight as long as your baggage doesn’t look massive.

Can’t help with the taxi situation unfortunately other than I know that Uber/FreeNow do work although not sure how consistently.