Building is a bit annoying I will explain

So I created a new save on the latest stable alpha build (559) and I encounter some hard time with designing my building.
First of all I didn’t know there is a limit to how big a template can be.
I reached a point that I just couldn’t add blocks.

Now the problems / annoying encounters I had :

  1. Designing between floors :
    So after building 2 floors I start making my stairs and zooming in between floors was hard I sometimes had a limit to how close I can zoom in (so I can look under the block and build).
    Sometimes I got an angle to place my block but since my camera was in a wall it randomly placed my block around the building.

2)I had an issue (not an error) that after designing a big chunk of my building and started working with some slabs 1 undo would delete my entire template and I had to start all over again , now this issue happen 3 times in a row when designing my huge main town hall.

I must admit I kinda got tilted and left the game (alt f4).

I still love this game taking in mind its still a work in progress but I just want to let you know what I encounter in order to fix those issues when working with designing my template.

Maybe make a way to remove parts of walls when designing? so if I forgot to make an opening for a storage tunnel (not a door just to make a hole in my wall or a hole in the floor) I will always be able to quickly make a way without deleting my entire design.
Also removing floor is possible but once you make another floor above it won’t let me , I don’t know if its a bug or this is how it works.

Edit: Oh and can I change the maximum template size I can make? I want to make a 1 template for my main town hall.