The Toilet Flush Problem Is This

It Does Not Flush Properly If Flushed Sereral Times In A Row( 10 Minutes Apart) Yes The Tank Fills Up To The Top. The Holes Are Clear, The Water Exits The Tank Fast. If The Toilet Is Not Used For Several Hours It Appears To Work Ok.

Could There Be A Problem With The Vent Going To The Roof?

When you state "Does Not Flush Properly..." do you mean that when you pull down on the handle, the water rushes into the bowl, but stays in the bowl for a while before draining?

If so, then you probably have a clog somewhere between the toilet and the plumbing prior to the main outlet. In that same bathroom, does the sink drain slowly also? Fill up the sink with water and let it go at once and see if it drains properly.

Also, check the bathtub if you have one. IF both of these drain properly, then it could be the vent stack leading to the roof. Auger this out.

However if it's only the toilet that drains slow, then it's a clog directly in the toilet drain pipe.

I would not worry about vent. Even though vent has its importance during displacement, it would be the last thing I would worry about.

You may have some object stuck inside the bowl or closet bend. Use plunger or 5' auger to make sure there is nothing inside the toilet.

Plunger is one of the best, cheapest, and simpliest, tools you can own. Unfortunately, plunger doesn't come with instructions. Many people don't know how to use plunger effectively.

You have a partial blockage in your sewer pipe. The fact that the toilet backs up indicates a blockage. The fact that if you wait long enough for that flush to drain through the blockage indicates that it is partial and not complete. The fact that you can flush, lets say 3 times in 10 minutes, indicates that it is far enough away for the pipe to hold 3 flushes. You can "guesstimate" the distance if you know the size of the pipe and the number of gallons of water you use each time you flush. Don't worry, it'll get worse. Time to snake out the sewer line.