I haven't played since a few days and this is the first game I played today.
I actually wasn't planning to post another game for a while but this one was really close and the lead changed a few times during the endgame.
I added a few comments and questions.

5: Fine. D15 would be a bit more common in pro games, because it's a big point to prevent white making a shimari, but F3 makes good shape with Q3 and is also a common pro move.

6: You don't normally see this because it leaves white some big weaknesses, and black can easily live under his stones later. You can aim at C6 and C5 depending on your surrounding stones, or aim to approach at C9 perhaps, or just take the corner easily with C3.

7: A little slow, but okay I think as it readies you to attack white's weak corner. I think J4 or K4 are a little better because you don't want to spend all these third line stones here - a high stone has a good relationship with Q3 and gets ready to attack a white approach there.

9: This is certainly a big area. I think C14 might be a little better, because white's pincer at D12 is generally quite annoying now. C14 will allow you to make a strong group here, ready to attack the D4 area, and immune to white attack.

11: Seems fine, white is making you strong for no good reason.

17: Bad! You don't need to protect this area, your stones are very strong becuase white has been scared and touched them repeatedly. You want to make shape with E10 (or maybe B10) instead, settling the shape by damaging white's stones. This way, you just make a strong group stronger, and white can play something like B11 to make the D10 stones have good shape instead of being a rubbish attachment to a strong stone.

20: This is a standard joseki shape. It is quite wide, and quite loose (which you can take advantage of), but also it is hard to attack and white can take R17 if black takes the side.

21: Quite big. R16 might be slightly better shape (maybe white P17 can live now). I would prefer maybe R8, to develop the 4-3 point side which currently is unfinished. By playing slowly, you give white sente to make the shape there good for him instead of you.

23: Bad! If you think his shape is weak and loose, the last thing you want to do is fix his weaknesses for him by making it strong and uncuttable. Instead, you should invade at R12 - white can do nothing, as S16 is well placed. Also, I think R4 is better, leaving white weaknesses at both R12 and R8 to take care of.

27: Sure, you pressed him down, but now he is strong and the Q12 thickness isn't actually doing much.

29: Seems too far. I don't think black has a great answer to white R3 now.

30: Bad for white. IF you can't cut, don't try to cut

43: Perhaps don't peep where you can aim to cut. Simply jumping is easier, and now you are strongly threatening to invade the C5 area.

47: Luckily you get to this shape point first

59: Very very very bad! You take 2 poitns in the F5 area. White takes 15 points in the corner! It is much better to play C3 and destroy the corner territory whilst making some of your own.

67: R4 seems like a better shape point. This way, white has some sente moves to stop you undercutting him.

71: Seems not good, white S15 T15 R16 (and similar) are a big problem for black.I prefer maybe R15, which has the threat of R11. I think H17 is even better, though - this is the last unfinished area, and white has some shape weaknesses so you can aim to mount a strong invasion.

73: Why not invade? This way you give white points, and don't take any of your own.

Thanks you two, this really helps a lot!

I actually thought about the invasions you mentioned but I was not sure how to continue from that.
The last times I invaded some area I lost the invading stones, actually that happend everytime I invaded tight areas.
I guess I need to improve an this a lot.