Thinking about leasing, just a few questions

I'm thinking about leasing a 335i or an M235i and will mod whichever car I decide to get. Just have a few questions:



1. I plan to lower the car, will I have to restore the to original springs when returning the car?



2. I plan to sign a three year lease 12k miles a year. Although 1.5 years in, I'm going to get promoted and will be highly interested in an M3 sedan. Will plan to lease that car as well. Will I have to pay a penalty to get into the M3, can I trasnfer the lease to someone else? What options do I have in switching here.



Thanks!