1. Yes you can as long as it is cash. i would advise setting up a LLC for tax purposes. Be VERY careful of what and where in detroit you buy, many areas of detroit are declining and WILL NOT make smart investments, BEWARE of scams as well.
2. title costs, repair costs, property preservation costs (snow removal, board up, winterization ect..) each home is case by case but always plan for 1-3,000 in costs not including repairs.
3. Yes you can buy as many homes as you wish, if you plan on more then 1 i would strongly recommend using a property management company to be your eyes and ears on the ground. Detroit is a ever-changing city and you will need local assistance to keep up with the tenants, market values, and property condition.
i have completed 150+ over seas transaction and have multiple homes and programs to custom fit each investor. Whether you are looking for yield or growth, rentals, flips, or land contracts we have a average of 14-19% ROI on our properties. Please contact me with more information of what you are looking for and i will be happy to assist you.