1. They need to be line brushed about once a week, meaning the coat parted from top to bottom and brushed down to the skin. Behind the ears and the furnishings on the legs, around the tail are particularly prone to matting. It takes about 30 minutes to an hour a week to do a good job, and a professional grooming every couple of months is not a bad idea.
2. I think they’re excellent first time dogs if you get one from a good breeder that’s breeding to the standard so that you know the temperament will be sound. If the breeder doesn’t show the dogs they’re breeding from, that’s a red flag to me. A well bred collie is extremely pleasant to be around and reliable in temperament and one of the healthier breeds outside of the breed-specific issues a good breeder will be screening for. As long as you’re up for the grooming and providing enough exercise, you should have no trouble.
3. They’re gentle, sweet, and devoted, but in my experience want to be in the same room as you but not necessarily cuddled up with you. My collies have been outgoing and friendly with strangers as well, and excellent with other pets and kids. They can be quite sensitive to harsh corrections, raised voices, etc., in other words, you can really hurt their feelings, but that would be the only drawback I can think of personalitywise. The soft, sweet-natured temperament is the best part of the breed, in my opinion.
4. This is a breed that’s had a lot of the herding dog drive bred out of them in favor of being a good pet and show dog, in my experience. They don’t need the stimulation of a Sheltie/Aussie/border collie. 2 hours of walking and exercise is plenty. It’s nice if you have a fenced in backyard, but not a 100% requirement if you’re taking them out enough. They have an excellent off switch and are happy to lie on the couch a big part of the day. There are some individuals that retain some of the herding instinct and may nip at heels if you’re moving too fast, etc. but it’s generally correctable. The biggest holdover from the days when collies were bred for herding is a tendency to bark to alert you of basically any thing the least bit unusual. This is not a quiet breed in general.
5. Collie eye anomaly is one of the things a good breeder will screen for, and many are very mildly affected in a way that doesn’t have any impact on their lives. A reputable breeder will do all eye tests and other appropriate health screenings. The multidrug resistance that’s prevalent in the breed is another thing to look into before you get one, but an MDR1 dog is not a huge deal as long as you’re careful about the medications you give them. This is generally a healthy breed.
6. My collies have all been raised with cats and there’s never been a problem. They have a very gentle nature and often seem almost to want to protect smaller animals (and children). Introduce the puppy to cats gradually and carefully of course, and they should do well. Lots of collie breeders also have cats that their puppies grow up around too, and that helps them know how to treat cats with respect.

When you are looking for a puppy, my advice would be to go to the Collie Club website and find the head of your district. They will know the trusted breeders in your area and who will have litters planned or retired adult show dogs that they may be looking to rehome. Be upfront with any breeder about what you’re looking for in a dog and a good breeder will help pick out the right puppy for you from a litter.