hi there,
im no expert but on the food front i would still continue with 2 meals as its such a long time to go throught the day with having 1 meal. i would also feed him earlier times like as soon as you get up in the morning and then have his last meal say between 3pm-4pm and he shouldnt need to go then last thing at night. altho as you've said about him being very timid etc it could be to do with him being nervous im sure once settled and a bit more confident perhaps this will calm down good luck with him poor love im sure you'll see the rewards in no time x