You can definitely make an offer on the house without a real estate agent, especially if you have found the property on your own. Your planning list is also pretty solid!
Yes you can. In fact your realtor would like appreciate your proactive approach. If you see a house you like, then you can ask your realtor to write up an offer on it.
Real estate agents can perform a sophisticated comparative market analysis to identify comps very precisely. But you can also find general comps yourself by looking online for recent sales in your neighborhood, finding the homes most similar to yours, and checking prices to see how much they sold for.
REALTORS® are negotiation experts. If you buy a home without an agent, you'll have to negotiate and decide how much to offer on your own. This may cause you to unknowingly overpay for your home – or lose out on one you want.
Can I write my own contract? Yes, you can write your own contract. However, including all necessary elements is crucial to make it legally binding.