Your best bet on a manual is Ebay. Some let you download one as soon as you buy it as well as mailing you one. Money well spent.
As for hydraulic oil, Yes being low will effect hydraulic operation. milky oil does indicate moisture and does needs to be changed. Most of those machines call for plain 10w30 engine oil in the chaincase/reservoir. They use wet clutches for drive. ATF or hydraulic oil could damage the clutches. Stop by your local Quick lube and see what they would charge for 5 gallons( or however much you need) of bulk oil. You can probably save a little money there.
The clutch adjustment is critical for proper operation. When properly adjusted, those clutch machines drive suprisingly well. If not, well, thier a pain in the ass to operate. When you get it sorted out Im sure you will like that machine.