This time I have managed to extrude the hole area by selecting "keep face togheter".
I only tried it on the cilinder

Exactely, I have the same problem as in image 2. I have tried keeping faces togheter, but to no result

Yes sorry, I was quite bussy recently with other projects.

I tried what have been sugested, keeping the faces togheter, but when I extrude face inside the edges from each face are still remaining...

Yes I have just discovered that. Thank you all for the responses

Thank you very much for all the support.

One last note.

What can you do if you want the horizontal middle line to be 35% from bottom and the rest 65% from top? Instead of 50%-50%. As well I...

When I am looking let's say side view, can I change my camera so it will show me the other side view?
Same for face. I would like to see the back, not the face. or the bottom, not the top.

Oh I have tried that but then again, what do you do with the remains of the edges of each face when you extrude inside?

I seen a guy doing an airplane engine and he used intrude in order to make the space inside a cilider for the propeler? Can you do this sort of thing in maya as well?

Second question would be, if...

Oh I see...

Is what I did correctly geometrical?

Also, how do I apply and commit? If I delete the latice it would reset my changes

I have managed to reach this but I can't seem to be able to manipulate in any way the object.