1. Yes, a baseline indicator (dot 5) is needed after the raised + in Ag+(aq) [in print the + sign is raised; the (aq) is at the baseline] to bring the reader back to the baseline of writing for the unspaced (aq). Same for Ag3+(aq) [the 3+ is raised; (aq) is printed on the baseline; no spaces].
2. The reason a baseline indicator is not used in BaCl2(s), for example, [the 2 is lowered] is because no subscript indicator is used for the 2 therefore no baseline indicator is needed before the unspaced (s).