Is Force Quitting Bad?

"Force Quitting" is not a bad thing, but that's not what you're doing. A Force Quit is when you exit an application that's not responding (Apple menu > Force Quit or keyboard shortcut).

What you are doing is a forced shut down. That can cause problems down the road, because forced shut downs can cause damage to the directory structure of the hard drive. You can check that in Utilities > Disk Utility by clicking Verify Disk. Usually, Disk Utility can repair the problems (you need to boot from the Install DVD or an external drive to do that), but sometimes a more powerful 3rd party utility, Disk Warrior, is needed. Directory damage doesn't happen every time, or even all that frequently, but forced shutdowns do increase the likelihood.

So, your best bet is to get to the root of the problem, if you can.

One question - when you close the lid, do you wait for a little while for the MBP to actually go to sleep? Look at the light on the lid latch - while that light is on steadily, the MBP is writing the contents of RAM to the hard disk (Safe Sleep). The MBP is only asleep after that's done, and the light starts pulsating. If you just close the lid, grab your MBP and take off you may interrupt the process by triggering the sudden motion sensor on the hard drive. That is one common cause of sleep/wake issues.

The duration of sleep is irrelevant. I'm asking what you do in the 30 seconds _immediately following closing the lid_. The latch light is not "always pulsing" - it is on steady for 30-60 seconds (longer time the more RAM you have installed) after you close the lid or otherwise activate sleep, then it starts pulsing. If it starts pulsing immediately when you close the lid, the normal behavior has been changed by altering the settings with Terminal commands or with 3rd party haxies.

Ammm...

About the sleep issue!
I found that if I close the lid again and wait for it to go to sleep again and then open again it works normally.
Had to do that a couple of times the other day though!

I used to leave my MBP on sometimes for several days, even weeks, just putting it to sleep when I was not using it, and had the same problem of it not awakening. Recently I had a problem with my its HD. The error was an invalid node structure, and had to reformat and reinstall everything.

I am still going over the possible things that caused that error. One of these maybe that I had to force shutdown it a few times, also due to issues with it not waking up.

Maybe it is not an issue at all, but you never know when little things like it may result in big problems.

Cheers!