Suggest you drive it first before you go for a reducing weight program. Most weight of the car is over the front axle and the passengers give weight to the rear. Which when it steps out unexpectedly say on a damp patch can be concernng. Good for hooligan spin turns though. My car is a 2012 version and has the same stick position as yours. It is not ideal and being further forward would be nice. Not tried a later version with the stick way forward so can't comment if that is too far or not. But as an ex racer myself I wouldn't worry about weight on this car before you have driven it.
As an aside I bought my wife a 1969 Lotus 51c not long after we got married. Makes a M3W look very chunky and heavy! Tweaks to the engine gave it 400bhp per ton.
