How does having bedbugs change things?

No need... ...To change anything. No matter what you've read, don't remove any furniture or throw away any clothes or possessions. Just a call a professional exterminator.
Nuisance. Itchy, highly unpleasant bites, but rarely cause any major disease.
Yes. Bed bugs bite at night and leave bite marks. If you develop allergy to bug saliva, you may develop hives or worse.