120i n43b20 170ps e88 2009 70k miles - leak and what i could change as well

[120ie87]

Hello all,

recently i bought an e88 m sport manual 170ps 120i, and there is a valve cover oil leak (above the exhaust manifold (...) ) in my n43b20 engine and i thought that i could change a few other parts as preventative maintenance as well.
What do you think? Which parts could be changed on the way to fix this valve cover oil leak? (Unfortunately there is virtually no service record for the past years for my car - and i dont trust service books as they can be altered easily by used car dealers or owners - it will be my project car).

i was thinking about ignition coils, spark plugs (as well as oil, oil filter, air filter, cabin filter).

There is no chain noise at start up from cold, so i guess it is not time for a timing chain set change yet.

Can you please tell me which other parts i could consider changing as i am fixing the valve cover oil leak ? Also are there any other common problems on N43 engine i should be aware of? (my previous 120i was the prefacelift model with n46b20 engine)

Thanks for your time in advance

-> ps. what about cleaning the injectors as well? (i dont know where they are located - my previous one was not the direct injection engine)