Barry Lyndon: 2-3 times a year in C to Europe should net you SEN status (probably the "best" *G status) - LH will credit you 225% of base miles flown once you reach FTL (35k miles, ie you're half way done already)

Status is valid 2 years, so even if you miss to requalify one year, you still get another chance.

If your 2-3 RTs include 1 connection within Europe in C as well (like FRA-ZRH or anything like that) then they'll net you around 32k miles - each RT. Thus, if you get to run 3 RTs every second year, you make 96k miles - easily rounding up to 100k with some more flights (which you seem to have) - if you only get 2 flights, you might not hit it every year, but as said before, M&M is only requiring you to qualify once every two years. And even with 2 RTs you MIGHT make 100k, if you get some more eco flights to Europe. Just take care to not book too cheap SQ flights, as they are rather stingy with miles, ok lah?

SEN seems to be rated higher than other *G on SQ according to my own experience - even FTL seems to get you better results of what a regular *S would get - after all, making FTL is double as hard as hitting *G on some cheap programs like A3, or around as easy as *G on TK

Never had trouble to get exit row on SQ even as a FTL, just asking nicely did it. With SEN, it was even easier. And flying LH/LX, the SEN status will of course be the best *G you could have.

So, there is really not much other choice but M&M for you. Hit FTL this year, then next year with the Exec. Bonus of 25%, you're ready to make SEN

Have fun!