Welcome to the forum.
The 2000rpm shifting difference is definitly is the Summer/winter switch.
As far as the Electric garage door opener you can control up to 3 different home systems forinstance Garage door, additional garage lighting and or interior security lighting.
As far as changing the security antitheft on the car,? Mercedes Benz wrote the book in this field. save your money. It is flawless! removing the resinator for, as Mike R. said about $100. You will like the sound but if loud is what your after that may not be the answer. If you take the money you can save on a additional security system you have a good start on adding enough horse power to get that sound where you'll like it. H/P= sound.
Enjoy your new ride it could very well be the finest automobile you will ever own...
Montana