I’m not sure you are really getting into here......you’ll spend a lot of time with students in the circuit. You’ll spend a lot of time doing trial lessons. We used to sell dozens at Xmas - now those get really dull after the 100 th....
you our talk of the more advanced ratings - well they cost money. And on an instructors pay ( bearing in mind you’ve paid almost £9k for your instructors ticket ) you won’t be keen to pay for more flying. Multi engine is fairly specialised and not that common.
i think you should get that PPL before you think any further, I’m not sure you are living in the real world at present TBH.