Doosan S75V advice

Hi everybody, I'm a newbie and hope to benefit from y'alls knowledge. I operated a Doosan S75V with 1750 hrs and I plan to buy it unless the issues below are show stoppers. - When 1st started blue smoke for 1 minute or less then clears up. - Radiator had no water / coolant visible. it was damp inside and there were no visible leaks. The engine stayed within normal temp range for the hour I ran it. - When dipstick is removed engine blows small droplets of oil out. (Yanmar 4TNV98-Z) - Hardly any visible vapor from filler cap but when it is installed loose I could see pressure bubbling around the cap. - The area below the turntable is damp with oil, but no drips seen. - Stick to coupler and boom to stick boom both have play. - It has hyd ran to the end of the stick, but I didn't find any typical thumb controller. It did have a foot pedal in the left side of the floor which activated hydraulics. I think this might be for a hammer but I'm just guessing. If I buy it I will definitely want to do what ever necessary to make a thumb work. - Battery light came on after 30 minutes and stayed on, but would still start. - Cracked front glass and no windshield wiper but the washer works well enough to squirt water up my nose. BTW I will use this machine to clean up my 66 acres which has areas which are overgrown with the biggest privet I''ve ever seen. I am also thinking about getting a hammer and a brushcutter or mulcher for it in the future. I appreciate any advice / comments and will upload pics after I figure out how to get them transferred from my phone. Thanks