Yeah, confirming that there is no max word limit (outside the 60K character thing that's in the forum code and out of my hands) and you can write those essays if you want. I just advise against it or recommend spoilers because some members here believe that you should be able to convey intent through your cards without having to explain.
If you post in this section, then yeah, no notes are required. Most you might have to do is tag threads, but as far as I'm concerned right now, you generally don't unless it's a custom format or something.
Well I'm not saying my Synopsis on each card is going to be super long, I'll likely just be noting things about my inspiration for the card if I think its applicable and talking about what other cards in the archetype it combos with the best and so on. Most of the writing will be in the Lore section of the cards (which I will try to lock behind spoilers if the forum allows for spoilers within spoilers) as there is a complex backstory to this archetype, unlike some others that I also have in mind to make after this one.