Id have Raised planter boxes put in around the outside of our yard so my mother in-law doesn't have to spend hours on the ground with a bad back to do the gardening!..

It could always be sanded back to the original. Hope it worked out!

depending on how often it's used and if the surface is too rough to walk on a cheap option would be loose gravel straight over the top but i actually think it looks like a carefully laid path in a beautiful Japanese garden and would add some mortar under the biggest loose pieces to keep it from being a trip hazard and admire it's beauty

Definitely agree with Amber Tiles above. Natural stone will require continuous sealing over their lifetime but it is an easy process and well worth it. The efflorescence are unfortunately unavoidable if the salt is in your paver/concrete. Get on to the sealer straight away and it actually prevents it from coming out all over the place. Are you concreting in the pavers? There is different trains of thought on efflorescence. You can wait for it to come out or you can seal it straight up. If you wait you will have to acid wash them down and let them dry prior to sealing. You may end up doing this anyway. Efflorescence take elbow grease to get off. 1 part hydrochloric acid to 10 parts water usually, with a scrubbing brush. As it's acid make sure you follow the instructions to clean stone down. I had to increase the acid proportion 1/5 to get the efflorescence off. *** It can etch the paver so trial it first. If you have a heated gurney wash it down using that. Tip: get the acid off straight away and dont do it in full sun. The acid if left to dry can stain your limestone a rust colour. Do a meter at a time. Use a good penetrating sealer and make sure you keep the name for future sake. Depending on the look you like get the appropriate sealer ie natural, wet look etc. Again, trial it first to see if its what you like. As for fence, monument is an awesome colour. Will bring the look of space in. Will be a big job. Are you doing this? Monument is a Colorbond colour. Nearly all brands of paint do it but each brand has a slightly different pigment base. If you do go this way, see if you can find out what brand your builders used and use the appropriate outdoor wood fence monument paint so the base pigment is the same. I hope this helped. Anneke