'07 250 EXCF - Some Questions from a Newbie

So, I took the plunge and now have 2007 EXC-F

Now, for a few questions, any help appreciated.

Clutch and brake fluid. The manual I received with the bike is the 2007 Owner Manual, and states that the 250EXCF uses DOT 5.1 for the Brembo clutch and brake circuits, DOT 4 can be used but should be replaced with 5.1 at the earliest chance. The covers for both clutch and brake master cylinders say use DOT 4 only. Any ideas how I can find out which is right ?

The clutch drags badly, the manual says it is self adjusting, being hydraulic it most certainly is. I have found a few posts on other forums suggesting bleeding the circuit, and removing, cleaning and lightly lubing the push rod. Any other thoughts?

Cleaning and lubing the air filter. The manual recommends Motorex Bio Dirt Remover and Motorex Liquid Bio Power respectively. Do you know of any other suitable products?

Exhaust packing. How often do you find this needs redoing ? The exhaust does sound louder than I had thought the standard system would, when pressing on.

Many thanks for your thoughts.

I have worked out how to remove the seat now to charge the battery...

DOT 5.1 and DOT 4 are basically the same and can be mixed, 5.1 has a higher boiling point. DO NOT use DOT 5, this is synthetic and the seals will swell.

Any foam filter oil/ cleaner will do the job. I've used Rock Oil in the past, Silkolene at the moment. Another option is to buy ready oiled filters, which is what I do until I have enough to make cleaning a batch of them worthwhile. (I hate cleaning filters)
HTH
Mark