RMTs don't use the Lv.50 BOTs' accounts to /shout, /yell, /tell thier Ads. Instead they use Lv.1 characters to do so.

IMO, making restriction to the chat commands to Lv.2 will reduce a good number of the Ads, sice they seem to delete the RMT-Ad character and re-create.

With any extra level, the more the spam is reduced.. so Lv.5 or Lv.10 will be enough to see actual results.