yeah - they're not perfectly efficient when charging. You have to put in about 150% of the capacity. So 1700 * 1.5 = 2550
You need a good 12 hours with that 200mA charger.
When they're fully charged, NiMH batteries can also generally handle a current of .05-0.1C (C is the capacity) and just safely release it as heat. So in the case of your 1700 mAh battery, about 170 mA on the high end. If you have access to a meter, it might be worth measuring the current output on the charger (make the meter part of the path with the battery charging).
The charger you have would definitely not qualify as a fast charger. A fast charger would run anywhere from 0.3 to 1.0 C (so in your case between 500 and 1700mA). Fast charging can slightly decrease the overall life of the battery (as in number of charges) but isn't anything to worry about. BUT, if not terminated at the right time - the battery can become damaged. You will feel the battery start to warm up when it's at capacity and is receiving too much current. In fact, the good chargers stop based on measuring temperature change.
So...as long as you're not in a rush, your charger is fine and you don't have to worry too much about the time. I wouldn't leave it permanently on but you won't do too much damage if you forget about it overnight. As far as when to stop - 12 hours or when the battery starts to warm a bit.