Condo vs townhouse: There are couple of options in a high-rise (135K, 2BR, 1 Bathroom, HOA $375, but includes Gas/Heat/Water + common things) as well as a townhouse (179K, 2BR-2 Bathroom, $270 HOA which includes only common things).
This is a matter of preference. For some only a single family home will do, others are okay with a condo. The benefit for a first time home owner is less maintenance risk/need. For a rental you are responsible for no maintenance. When you buy a town home or condo, you typically do not worry about outside items. True there may be a special assessment, but they are typically announced well in advance giving a person time to save.
Price range: I'm looking for 100K-200K. Which price range might be a better investment for later (highest return)?
Its very difficult to tell, and this question is very broad. Are you buying in a neighborhood that will experience gentrification or is on the slide downward? Those are typically the key to good investment properties. One thing to keep in mind is that it is expensive to sell real estate. In order to break even on a 100K property, you will need about 15% increase in sales price. With the 200K property, probably like a 9% increase to also break even.
Better Sell/investment: What would be things that buyers would look at most? e.g. 2 bathroom vs 1 bathroom is much preferred, 2nd floor vs 1st floor, attached garage, anything.
Location is everything. 2 bathrooms are nice, as well as other amenities, but location, location, location.
mortgage terms: Better to get 15yr (3.75%) or 30yr mortgare (4.xx%) with current US economy? Payments won't be a problem. Just think from investment perspective and less I would lose.
Either way the economy today will not be the economy 5 years from now. For me, the 15 year is almost always better. You build equity quickly and pay a lower interest rate. The new tax law greatly diminished the interest rate deduction so that is not a factor for many people.
This sounds like a starter home for you notching another vote in the 15 year. Lets say you want to move in 7 years. With the 15 year, about 65% of the original loan balance will be gone. On the 30 year, only about 21%. With closing costs, and the 30 year, there will likely be little to apply towards the purchase of your next home from the proceeds of the sale of the starter home.
Lets say it is not a starter home. Do you think you will increase your income in the next 10 years? Probably very likely. With a bit of extra payments a 15 year can often be paid off a little early say 10 years or so. Then you would have the additional financial security of having a paid for home. It is an amazing position to be in.
Others will tell you to invest the difference in payment between the 30 year and 15 year, but I do not think that is suitable for most people. Think of the 15 year mortgage as a nice diversification investment.