Does a Leasing agreement change along with the new company?

Leases are assigned from your old LL to your new one at closing. So are security deposits. So, no, your rights and obligations are exactly as stated in your Lease, no matter how many times your apartments are bought and sold or property management companies are hired / fired. It's a common urban myth that tenants have different rights or can terminate their Leases merely because the apartment community has been sold.

I agree with the previous response by Mr. Lautin. If they intend to improve the property and increase the rent, they have to give you notice of same at the end of your lease period. However, you should have the option to stay there if you are willing to incur the increased rent once it is renovated. Good LLs offer an amount of rent as an incentive to leave earlier if you choose to do so. Good luck!