If you have smoke escaping around the lid while it’s cutting or engraving, you likely have a venting issue. Properly vented it will be under negative pressure so air flows into the machine and out the exhaust. It will only come out from the lid or door if it’s under positive pressure - either the exhaust fan isn’t working or you’re not venting properly. Common causes are too long a hose with too many bends (use the supplied length with no more than two 90degree bends) or a closed flap on your vent outlet.
As for the overheating, the basic model has a max ambient temperature of 75 degrees. Over that and it won’t run. Under that it may pause to cool during jobs and do that more often the closer ambient air is to 75F.