This made me smile. BA Silver is a lot like SEN, except the lounges are better, and the business class seats are better. Lufthansa-esque Business Class can still be had on BA (WTP ;-) ) if you miss it.

Lufthansa's FTL is only good for lounge access to LHs lounges - I wouldn't, and am not dong anything to retain it. The lounges are okay, the processed meat in the food on offer is salty and tasteless.

I would look into Priority Pass in your position - or an AMEX PLAT card, if you think that it is worth it for you.