Does anyone actually use mercenaries in the campaign? They seem like a huge waste of credits to me. You get a lot more mileage from regular unit upgrades.
I totally use mercs all the time. I don't buy the mercs that I won't use (I.e. I have the marine by default, then buy the siege tank and either the viking or banshee (depending on last mission choice)), but the ones I do have I spam out as much as I can. Really, they're instant-build beefed up units that cost close to what the original would cost anyway (4 "War Dog" marines cost 250 minerals as opposed to the 200 minerals of 4 regular marines). Not to mention, you don't even have to tech to them in the first place. I rarely if ever build siege tanks regularly, but it is just about no investment to just pull 4 siege breakers out of your rear then siege 'em up.
Really it's all Blizzard's fault for just hosting the maps in the first place. If they didn't host the maps, they wouldn't have much control over the content of maps, but they wouldn't be able to be held liable for it. The reason they do this is not only because they can, but because they have to or their precious little Teen rating will be bumped up to Mature.
Maybe Blizzard is hosting all of the games themselves because a lot of people had issue hosting in the earlier battle.net? If you
do want to play a popular game today, it is much easier to play one than in warcraft 3's days. There were a lot of firewall issues back in the days that prevented hosting, and while a lot of them were easy to fix, a lot of them weren't. Having Blizzard host everything is the only way to actually get around the issue, and now anyone who wants to play a game can start up a room of it, whether or not they have played it before.
Actually, the enemy wont target the SCV's, because they wont be doing actual damage. Its usually a good idea to send atleast a few SCV's to repair any mechanic things, especially Thors.
The AI sure loves killing my medivacs first... my whole team of marauders and marines left almost untouched, and three medivacs got shot down first. Are you talking about humans or AIs leaving SCVs alone?
Well, I mostly think its the players, if you just issue an attack order, the guys will attack everything in their range, but the priority goes for the ones that fight back. But, I think the AI, because it can be pretty efficient in micro, might be targeting the medivacs. .
I mean, the APM of an insane AI ranges from 1000 to 2000. :S
Depends on the AI you play against, I think. I've had my SCVs target fired while repairing stuff (mainly the "Odin") many, many times while playing on Brutal. I also remember the zealots going for my SCVs repairing bunkers in the "Rush" challenge, however only if the SCVs were relatively close to the zealots.
And as for shooting down medivacs: That's standard. If a guy is ordered to a-move to a spot and he comes across 2 enemies, one which is flying and one which is not, he'll attack the flying unit first. If you want your medivacs to be safe, keep them in the back of your M&M ball.