From my experience -
1. No need to shop around for realtors as long as he/she sends you to the updated listing and not pushy. You find houses in zillow, redfin, trulia send the list to realtor and go see the house in your free time.
2. Not a good idea.
3. Compare house prices in the website I mentioned above, see what are things comes up during inspection and then do the negotiation. For e.g. - if during inspection, you find some mold or a/c not as good as the seller claims , or damage on roof , anything that would cost a good amt to fix, add these up and also add 10-25 K on top of that, deduct this from house price and then offer. This might go back n forth like a car buying which is normal. If your realtor hesitates to do this, fire him.
4. New appliances , updated Kitchen, updated bathrooms, updated floors.
5. Watch HGTV house hunters in youtube or netflix, see what a buyer demands, you can get a lot of ideas from these shows.

Here's what I do when I go look for a house

1. See spots for termites, molds, water damange
2. Walk inside the house specially at the corner of rooms, curve of stairs, places where there could be a lot of movement, like where the couch was or bed was and HEAR for any crack noise, if you can hear that noise despite someone talking in the same room or while the music is on then there might be a damage there.
2. If the house you saw has lot of air fresher then something fishy is going on
3. How old the house is and how many people owned it, less owner is better
4. Avoid buying rental properties unless get a good price.
7. I am always present during inspection, ask questions, go around the house with the inspector and remember INSPECTION IS A VERY IMPORTANT THING WHILE BUYING A HOUSE.

PS: I own and co-own several houses.