Forester AWD fuse

I own a 2nd hand 1998 Forester S, which I bought last year. It has been running pretty well until recently. I brought it in to have the oxygen sensor and both front CV boots replaced yesterday. The mechanic mentioned that there were some vibrations while turning that I had not noticed before, that may be caused by the clutch not catching properly. It supposedly improved when they put in the fuse to cause the FWD light to come on. I'm going to need to take the car on a long trip soon, and they told me this should be ok, as long as I stay on the paved roads.

I have never owned a vehicle with AWD before, so I did some digging online, and read that this is a temporary fix (in case of flats), and that I should not drive for a long distance with the fuse in because it will cause additional wear on the drive train. I would like to find out if this is true if I stay on the roads where the AWD should not engage.

Any recommendations about what the problem with the AWD could be, and if I should take the car on a long trip at all in this condition? I could pull out the fuse and try driving it to see what the problem is, but whatever it was it didn't happen (or wasn't sufficient to cause me to notice) before they tinkered with my car yesterday.

Hello,sounds to me that this wasn't a Subaru dealer that gave you this info.I would not take a long trip with the FWD light engaged as this has disabled your all-wheel drive.According to the owners manual this is only to be used when mounting the donut spare tire.You could have a problem with the AWD
transfer case that distributes the power to all your wheels.Also whenever you have to replace your CV boots obviously they have been torn and allowed
contaminents and rain to get into them possibly damaging the joints.Hope this was a little helpful