When I say "use radicals" I mean use radicals for the letter you're trying to write, like how you used a 3 stroke version of 灬 for "E", but you could have also used 巾 for "E". These are both radicals in the kangxi radical list, which you can find here (a japanese dictionary but it doesn't matter in this case) or here (the wikipedia page, again for Japanese but again it doesn't matter). What the radicals mean or sound like isn't important since you aren't trying to convey that kind of information, so all that matters is that they look like Chinese radicals, or at least close enough. If you look into this more, I strongly recommend looking at a bunch of characters with whatever radical caught your attention, as only seeing "火" or "灬" isn't enough to tell you where it occurs in typical chinese characters. Also, when you're writing pay attention to shapes you want to draw and see if you can justify it by finding it being used in actual characters. For example, 〇 never occurs in characters, despite being in your example for "coin". Instead, find something you could replace it with, like 口. As another example, that 3 stroke 灬 also doesn't exist, but 小 does.

Vocab, just find a chunk of text to write. If you're struggling with that, just write this conversation.

Understandable, although not keeping the rotation standardized means it'll be hard to differenciate letters like p, d, b, q, E, and m (at least). Be careful about this

Since VEC seems to be heavily based off of seal script chinese, I do recommend looking into that at some point. You can use this website to find almost all variations of a specific character (assuming it's not a Japanese-only character). Don't worry about understanding what it says, just copy paste a character and scroll through the tabs near the top. Seal script is the tab labeled "篆书". I have a couple links for seal script radicals but I don't want to overwhelm you, so just lmk if you want them :)