Heya, I was also looking into that tileset for RPG maker and came across your query here.
I have not purchased it yet, but in the free version of it, they have separate files for MV that you can use directly. But I will reply to your queries individually.
- How to split the tileset into MV’s required formats?
You will need to use any software that allows you to edit pixel art (there are a lot of digital art ones, but you need one that can handle pixel art, like aseprite, photoshop or piskel etc.). Open the existing tileset you have with RPG Maker MV in one window (these are in the folder of your game/program) and open the Limezu tileset in another window (of same program). You can then use selection tool to highlight the area of any particular tile and then copy paste it across windows with ctrl+c and ctrl+v into a new layer. Align your pasted content with the original tilesheet (remember to do it in a separate layer, so you can just hide the original later when you are done). Enabling a grid (set to 48x48 pixels) helps a lot during alignment, so do that too!
- Which sheets belong to A1, A2, A3, A4, A5, B, C, D, E?
This is a question you can only answer if you understand what each tileset means. You can read for about it here https://rmmv.neocities.org/page/01_11_01#p02 rpg maker mv. In RPG maker MV and MZ: 1 tile = 48 pixels. And animated tiles (in tileset) have 3 frames max. This is a limitation with limezu tileset because some of their animations take up more than 3 frames. There are still ways to use them, but thats beyond the scope of this answer.
In simple words: A1 to A5 are basically base tiles that make up the map, they are also autotiles, with A1 having animated autotiles. Autotiles are tiles that if you place them next to each other they combine together automatically to create a design. Like placing two water tiles together and they combine to form a pond of water. And the more tiles you add, the larger the water body gets. This is different from other tiles that are single place, as in you place two plate tiles together but they don't combine to form a tray. Tile types B,C,D,E are all single place tiles, they will not interact with each other when placed next to each other. (you can find many youtube videos on this that are very helpful).
- Any tips to avoid blurry tiles or wrong scaling?
Depends on what software you are using, but:
1) always scale up in multiples, eg multiplied by 2 or multiplied by 3. Don't just change values randomly. If you are scaling up a 16x16 image, 2x of that would be 32x32 and 3x would be 48x48. Rpg Maker MV has system of 1 tile = 48 pixels.
2) use the nearest neighbor setting for scaling. It might be hard to explain what it does in simple words, but basically if you scale an image, it allows for smooth scaling.
3) If you have a whole sheet full of smaller sized tiles, don't try to enlarge each one with manual transform tool (that can lead to errors that are easy to miss and annoying to fix), instead enlarge the whole image. (you can search how to do it for your own software by googling it.) Eg. in aseprite you can do this by:go to Sprite > Sprite Size and select "Nearest-neighbor" interpolation to avoid blurriness.
- Best practices for organizing LimeZu tiles in an MV project?
Unfortunately as I mentioned at the start, I haven't actively worked with this set, so I cant offer much.
Hope this helps. Its been a while since you posted so I am not sure if you still need this help, but I hope for anyone else googling regarding this, my answer at least helps them.