1. First talk to few realtors. See what they bring to the table. Most will say they will send you list of homes per your criteria. Some might claim they get dibs on homes that aren't even listed in MLS system yet. To me, the best one would be the realtor who can give a portion of their commission to you. They get 2-3% commission, some offer 0.5-1% back to buyers.

2. Bad idea. I don't know if one agent can represent both buyers and sellers, but conflict of interest tells me its a bad idea.

3. Depends upon the market. It is offseason right now, but still is a seller market in many part of the countries. if the inventory is high then you can offer low (depends upon how long the house is in the market) otherwise the asking price.

4. That's upto you. Some things people don't look into: is it in flood zone? Things people look into: what kind of school? How far is the grocery etc.

5. Any other questions?

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.

here is my experience
a) location : some places multiple offers and more than asking price
usually those places nearby good schools, parks and freeways.
b)Do bargain with your agent they give you closing cost.
c) find good lender (my case closed in 2 weeks) i noticed some of then take several months too
d) take time and see house so you will get an idea on whats going on.. if you like then other person like too..
e) usually if you go nearby million (in high expensive area) then can put offer less than asking price
f) but in real scenario first time home buyer can afford average market price house so there too many buyer on that price range.
g) your agent may busy with others too just keep looking in redfin as soon as it hits your criteria go see and put an offer.
h) good luck