Yes, Ant Man is indeed an Avenger in the comics. He's been part of the team on multiple occasions and has played important roles in various storylines.
Well, Ant Man's strength in the comics varies depending on the situation. He has the ability to shrink to microscopic sizes while retaining his normal strength, giving him an advantage in certain scenarios. Plus, his communication and control over ants can be a strategic asset.
In some comic runs, Ant Man does meet his demise. However, comic storylines are complex and often subject to reboots and alternate timelines, so it's not a straightforward yes or no answer.