This is not correct. Read-modify-write essentially never happens with ZFS unless you’ve set ashift lower than the actual physical sector boundaries on the underlying media.
I’m not sure how many configurations I can offer for a single-disk pool… but you probably don’t need L2ARC or SLOG for the most part. On the other hand, an L2ARC configured with secondarycache=metadata might be useful, particularly during cold boots before the ARC is hot.