I think the biggest problem with remodeling an old house is the updated codes. Cosmetic fixes are one thing but as soon as you are forced to pull a permit the "can of worms" can be opened.
I had a friend who bought an older home that he planned to update and flip for a profit. He got a really good deal on the purchase price of the house and thought he would have no problem making a profit with a little sweat equity. Turned out there was asbestos in the siding, galvanized pipe for plumbing, the boiler for the hot water heat was shot, aluminum wiring through out the house, the electrical service was too small for finishing the basement, the ceiling heights were too low, the stairs too narrow and too steep, no escape windows in the basement, the house was under insulated, the roof had three layers of roofing on it, the driveway was slopped towards the house foundation. the main sewer line was cracked to the street and the windows were single pane..........other than that.......no problems! MAKE SURE YOU GET A GOOD HOME INSPECTOR for an older home purchase. Well and septic in a rural setting are another issue. I'd stay away from anything older than 1980's