Durabilities only affects the divination buff, but I dont like that buff anyway because it give some chance to turn you into a fisherman which has some glitchs(slower movement speed, unable to attack sometimes). If you want the buff, you can always go to someone else's island to receive it. Other than that, having a burning island doesn't give any bad effect, although it may discourages you from maitaining your island.
One thing I learnt from this game is that sometimes, you need to change yourself to adapt to the game rather than asking devs to change the game so it will fit for you. If you aren't AP buyer and dont have a highbie character who can make a lot of gold, then you shouldn't care about the island's durability.
I only go to my island once a day to fishing(10 pulls to receive 50exp), visit a lv2 or lv3 island to fishing on the small islands(25 pulls to receive 50exp), collect hammers and oclay. You shouldn't use the hammers and oclay right away, instead store them in your backpack. The fishes you got can give some hammers too. When you have 15 hammers, use them all at once(receive 1-3exp for each repair and 50exp for daily event = ~80exp in total). Check the alchemy table daily, when you see the +8% crit damage stone on round 3, its time to use the olcays you have accummulated. Hehe, I have never been able to make that stone but it worth 1-2k gold so it may be worth your patience. I have successfully made a +3 VIT stone(sold for 300G on AH), a +6 STR +3 AGI stone, a saphael mat x2 on round 5(sold for 120G) and several moon, sun platinum fragment x60(sold for 50G on AH) from the oclays I received from my island in less than one month, quite an income for poorbies XD.