N900 is a phone. 99% of the people who buy the N900 buy it because it is a mobile phone. That it can receive make calls. If it couldn't, I'm sure it wouldn't have been as popular. Actually, you will have about 90% less people in this forum that of now if it couldn't make or receive calls and sms. Gawd, I just don't get why people say N900 is not a phone. My N95 8GB could be said the same thing then. It can play videos, take photos, record videos, play music, skype, msn, browse, voice navigation etc etc. So it must not be a phone eh? Anyways....

I don't have the issues that the OP mentioned.

I regularly watch videos on my N900. Actually, VERY often.
I've never missed a single call while I'm watching a video.
It always pauses my video and I can receive the call fine.
Also, even when overclocked to 1GHz, mine never locks up.
Finally, the speaker on mine is quite good. Similar to my N95 8GB.
I would have definitely hate my N900 if I couldn't rely on it as a "phone".