Backround/Avatar: I actually really like your bg/avatar, so yeahh good job on that
Video Quality: I'd try to invest in a better camera or lighting, especially in the latest one video, although I think that was a good topic. Work on your jump cuts, you seem to be cutting it too close so the last bit of sound at the end is cut off. Move around more in the frame between cuts.
I'd try and be a bit more loud/energetic and at some parts in the audio I had a bit of trouble understanding.
Topics/Ideas: I really like your topics/ideas, they're good.
Overall: You're clearly doing a bunch right, 45 subs in 2 months is not at all bad :].