Iemand een idee hoe dit (het beste) opgelost kan worden?

very easy to adjust. loosen the 2 triple square (don't use a star bit or flat head as you will strip it) on the latch that's on the body. Move it just a little and tighten. Try closing. Repeat until the door closes easily

The hinges are not really adjustable, the door has tapered cones that sink into the pre-set tapered cup on the A-pillars then held down with 4 special screws.

They are some of the most robust hinges on the market, same ones used on coupe & convertible models, they never really wear, 10 years is nothing for what they are capable of.

To test hinges simply try lifting the lower, most outer edge of the door and see if there is play, even if there is, 99% certain that a quick tighten of the screws would cure this.

However, from what you are saying about the door needing a good swing (sounds like fun) then I am 100% certain it won't be a lubrication or hinge issue. It will be the striker plates have moved inbound fractionally.

The striker plates are what the door latches catch onto, if too far inbound the latch will not active and lock-on correctly; a firm push would be required.

Take a close look at these; they are the Chrome loops that sit on the B-pillar halfway up.

You will notice they are affixed with 2 x spline-drive bolts (DO NOT BE TEMPTED TO USE THE INCORRECT TOOL ON THESE, USE SPLINE-DRIVE KEYS ONLY, they are like butter!) you will also notice there a settings top and bottom (vertical lines)

Setting is easy and obvious - the door should follow the contour of the rear quarter panel. Many body technicians work on a fish-gill basis, this means the rear edge of each panel protrudes out about 0.5mm over the next panel and this aids aerodynamics.