Looking for some guidance I hopefully didn't overlook in the FAQ. Here's my question:

Scenario: I'm at 46 nights stayed in 2013 and currently Silver status. I just arrived at the Beijing Marriott NE where I will be for the next 15 days, and during this stay I will reach the 50 stay mark and thus, Gold status.

Two questions:
1. When will Gold status take effect? For example, when I reach 50 nights will Marriott change my points bump from 20% to 25% for each night after 50?

2. If I want to use the Executive Lounge here or get a room upgrade as typically given to Gold status members, is that something reception would handle or require me to go down and ask, or worse yet, check out and check back in?

I'm asking because I'm rather frustrated that after staying in this hotel for 45 nights throughout this year, I just had my worst experience checking in and was given the worst room I've ever had here...