I'm really sorry to hear of your situation Bioman, you've got my sympathies

I don't think you can make a judgement based on the amount of rosettes - all that really means is they've shown a pig, on one day, which was better than the rest, it doesn't necessarily equal a good reputation as a breeder or guarentee healthy pigs.
Gut instinct, every time

Look at the conditions the pigs are being kept in, see the parents, brothers and sisters from previous litters and ask them about their health status/vet plan - good, reputable breeders will be only too happy to answer (if they've not already volunteered the info).
I would also suggest you go back to the breeder you've bought these pigs from and tell them what's happened - they may not be aware (and horrified that this has happened with their pigs) or they may not care (in which case they
should be reported to the BPA or trading standards).
I also wouldn't say straight off to be wary of buying pigs that are indoors

My piglets are born inside, stay inside for around a week then go out to the field with mum. However, when I wean them I bring the piglets into the shed. This serves a number of purposes
1) It keeps them out of sight and sound of mum
2) It lets me observe them closely for signs of ill health or problems before they go
3) It lets us get up close and socialise them a bit
4) It's so much easier to catch them in the shed

Ever tried catching 8 week old weaners in an acre paddock while the new owners are waiting ?

I would advise any new pig keepers to go either on a personal recommendation from someone who knows what they're talking about or to visit a few breeders and have a look - those with nothing to hide won't mind showing you round and won't put you under any pressure to buy - in fact, they'll probably become a great source of advice and information. A great thing for a newbie to have

Karen x