As in many situations, both TV and real life, things are sometimes only funny if you're already familiar with the characters/people involved. For example, just in the first clip, if you didn't already know what kind of person (barely) that Sheldon (barely) is, it would seem more like "what a jerk."

Sometimes.

The next time when I rewatch the show, I'll have to try to 'cut out' the laugh track.

Even when I think a show is hilarious, I'm not LOLing all the time, because I'm paying attention to the show so I don't miss anything!

Never watched without a laugh track; but, when it comes to what's funny and what isn't: Sometimes the track has laughed at things when I didn't...and sometimes I've laughed at things when the track didn't...and sometimes both our "funny bones" were tickled.

Also, when re-watching, sometime I even start in anticipation of what is about to come; BEFORE the scene, OR the laugh track shows up.

As for whether the show is funny…

Over the years, many, many, many shows with laugh tracks have bitten the dust—some after only a few airings. So, if something isn't funny, I don’t think there are enough laugh tracks on the planet to keep it on the air for 12 seasons.