Slight play in one of the ball joints

I had a full service on my Renault Clio 2007 Dynamique last week. There were a couple of advisories: Slight play in steering rack & slight play in one of the ball joints. Also a rusty hole in the sub frame and brake fluid needs changing. Now the last 2 problems the mechanic said to wait about a month then get it fixed. And the first 2 problems (slight play) the mechanic said to wait until november, see if it passes the mot and just wait until it gets really bad. I'm just worried that this is a long time and would rather get it all fixed ASAP. Is this reasonable? Is it dangerous to wait like the garage said?