1)
Wow ok, just I just reproduced the first bug : I have to build some units then click on a building and boom !2)
I reproduced the second when trying to quit the game and having a unit selected in the sandbox tab.Fixed and reuploaded ! 
Thanks for your feedbacks !
About the sandbox :The sandbox is totally a debug tool, so I will only keep it in future versions for debug purposes and the menu will be hidden.
(in fact, all the tabs you see on the right are
only for debug)
I plan to add much simpler tool, probably in the army editor or near, to test units fighting with others, displaying some stats, for army tuning purposes (for maths nerds

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About horses (and units in general) :All units have to respect a certain size (which is 8x3xheight[8-12]) so for now they will be small. It's part of the graphical choices I made at the beginning of the project. I didn't want to have enormous mounts and wanted to keep units quite simple.
The goal is to design beautiful and stunning units with only a few cubes (which was hard when I started designing this default army. lookt at the blocks editor, there is a probable some spongebob characters

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Despite the graphical choice, there is also a very critical strategy aim : when you'll fight online, you'll meet totally different armies, in design and in abilities. So I don't want to add another layer of complexity when dealing with enemies units, too big to take a path or another, blabla. It will be hard enough to find which strategy to use against other armies
About buildings :Their size is a mix of graphical choice and game design problems.
When I began working on the game, I used little boxes for buildings. They were in 3d and every other things was 2d. And it was graphically effective. So I decided to keep this unreal aspect ratio between units and buildings when I switched to full 3d. After all, in every RTS the buildings aspect is totally unreal, warcraft, starcraft, ... and I like the way it is ! Like for units, it's much much easier to design a 8x8x12 cubes building than a 32x32x24 building !
For the game design aspect, it's due to the army tuning : when you create a building and set abilities, stats, design, etc. why would a building be bigger than another one ? How should I calculate building size according to abilities ? The more abilities -> the bigger ? What should be the step between a building taking 1 tile to a building taking 4-square tiles ? But on the other way, you could recognize important enemies' buildings only by their size ?
Some questions are still unanswered, but for now I try to keep some aspects simple.
I am totally not closed to the aspects of sizes, but it is too son.
And I have a lot of ideas to implement, so I must calm down on functionalities to focus on a effective and stable version.
And later we'll see.
If the game is a success (

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