In resulted pdf there're weird spacings all over the document. Figures are referenced by manually indexing them rather by name. No hyperlinks. Equations have no numbering. Some equations/formulas in text aren't using math mode. (For units better use the siunitx package.) Bibliography is basically simple text rather generated, making it hard to switch to other styles.

Regarding the editor, seems math and text cannot be written together. Copying math and pasting to text field results in pasting LaTeX code.

Now if just said made this because wanted to wouldn't have mentioned it, but as you provide a reasoning, LyX (LaTeX frontend) and TeXmacs (not frontend but can export to LaTeX) provide a way to get LaTeX documents without writing LaTeX.

Overall the site can function as cool math-enabled notepad but (for now at least) seems hard to use it as platform to author papers.