A. There is a limit of a character not appearing in more than 4 titles (not counting multiverse) and he currently will appear in 3. I edit the STEEL line, so just pm me you pitch.

B. While I like to use current or former DC writers/artists, you can use writer/artist not of DC. There are no restrictions based on their use in AoM.

C. You can use characters not native to DCU in NEW DAWN. If you wanted to use a Vertigo character in an Aquaman series for example that is fine. Like you said, I'm using Spider Jerusalem in SUPERMAN and he's the newest member of the Daily Planet staff.

D. For INFINITE DAWN line (formerly Multiverse line), you would pm the line editors clark_kent and lorec. There are no restrictions of character use for multiverse titles even if they appear in several other titles.