I was told by an "old salt" yesterday that putting the wind to beam with just enough wind in the sail to prevent flogging will help. I'll also go over the furling system today and do some lubing as the PO told me the boat hadn't been used much in the last 3 years, so I think I know what that might mean in terms of maintenance.
We had exactly the problems you are having; with a brand new Harken unint 2.5. Here are some comments about it:
1. Dont "lube" anything! Harken furlers are designed to be run without lubrication on the bearings; so the worst thing you can do is put lube in! Give them a generous washing with a spray nozzle after each sail and that's all they should need.
2. You should be able to reef or furl a flogging headsail; if you can't there is something wrong. It might take a strong pull it to furl but it should be do-able without a winch. We can reef our headail in 30-40 kts of wind (now).
3. When fruling the sail it is easiest done while sailing nearly DDW. If you steer downwind until the headsail just begins to luff due to shadowing from the main it will ease the windload and allow the sail to furl more easily. If you are having problems with a "stuck" furler this is a good way to get the load off of the sail and hopefully reduce the amount of force needed to get it to roll up.
4. Heavy dacron sails are more difficult to reef or furl than light ones. My 105% yankee cut is heavy dacron and it requires more than twice the force as the light 125%.
Here are the problems we had to solve:
1. There was no wire pennant between the top of the genoa and the swivel; so the halyard was too long and was getting wrapped around the foil above the swivel. Adding a pennant eliminated the "jamming" due to this.
2. The headstay tension was not adequate for the heavy dacron sail. The headstay was sagging while the sail was hoisted. The flex in the foil was preventing it from rotating easily. Adding backstay tension helped reduce this "friction". If you have a hydraulic backstay tensioner; make sure it is tight before you furl the headsail.
3. Luff tension needs to be adequate in order for the weight of the sail to be supported along the luff instead of on the foil. We always tension the luff before we leave the dock and slacken it after we return. If we don't have adequate luff tension it requires mor effort to pull the furling line when it comes time to reef or furl, so I know this is a big factor on our boat.