For issue one, you may as well just take the air-box off... You'll get pretty much the same dead spot.
Otherwise as said above, try 'un-modding' the box you have in the mean time.
My 250 does exactly the same, only difference is, the air-box isn't even on it at the moment.
**EDIT**
Actually, you'll probably find that a 250 airbox would do the job as well. Same Chassis, different displacement engine, and in all likelyhood Suzuki probably just used the same airbox.
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