On the other hand, it has some advantages for the established politicians as well, after all they set the rules for this system - in essence it avoids an arms race. Lifting the limits would give them some advantage over the smaller parties and upstarts, but nothing over their real competition, but that would mean that all the major players would suddenly need to raise many times more money, making everyone more dependent on donors.
Who are the losers in this case? Probably the very wealthiest individuals (not "the 1%" but the top 10-100 richest people), since it limits their influence. At any one point of time one or another party (not necessarily the largest one) may have an advantage in financial support and would be happy to lift or raise limits so that they could buy more votes, but if something like that happens, then it motivates everyone else to not let that happen.
Regarding your questions - it depends, that's more a question for the lawyers. IMHO ads supporting some issue would be fine but talk hosts arguing in favor of some (any) candidate would be prohibited in pre-election campaign time window - e.g. all mass media interviews with candidates during that time would be only in the scheduled slots or as advertising. Sure, if you control important media or people then the limits can and do get bent quite a bit beyond their intent, but it still sets a limit. I mean, if the stated limit is 10 then everybody might push it to 11 by various means, but you can't really do a meaningful large scale money-influence campaign without it being obviously illegal.
