I can confirm that only Turquesa has the dress code requiring long pants and a collared shirt of the four restaurants available - and only for dinner. A nice collared tie die T-shirt or a hawaian style shirt and jeans or dockers has served for me. I do bring a pair of nice shoes, but i think sneakers would get by. You could always avoid this restaurant, or even ask them to serve you off of their menu in your room or outside at the grill while you watch a show - we stay there because they can be very accommodating. They once served us dinner from the italian menu at a table right next to the show, decorated with balloons, sparkles, ribbons etc. for my daughter's 18th birthday, then worked her into the show.
Frankly we find the service and facilities at the Palace outstanding, and the food good, but for a real good meal we head into town for Kinta or a few other places, and just not worry about the "paid for" meal. It also makes a nice break in a week or more and a chance to get out in town.
The other comments above are accurate, but I will add that they keep a few towels at the door, and
regularly rush to cover my fabric chair (at Turquesa, which doubles as the lunch time indoor restaurant) with one at lunch when I obviously just got back from diving, then jumped in the pool to rinse off, then put on a shirt and flip flops or dive boots and joined my family for lunch (which is basically every day). I do tip, and many don't, and of course YMMV but it seems to work for us.
Have a great time! We'll just miss you - arriving on April 10th for 9 nights.
---------- Post added March 17th, 2014 at 08:21 PM ----------
While I respect the dress codes in places like the Palace, I no longer respect their no-tipping policies after finding out that employees are paid crappy wages with the hope that they'll make it up in tips. They don't realize that guests are actually being told not to tip, that the tips are supposedly included in the room rate.
I've stayed there 4 times - nobody ever told me not to tip. I was once asked to make a contribution to an employee "emergency" or some such fund at the desk, but certainly have never been discouraged in any way from tipping. We don't tip big, but we tip a little very regularly. A wet dollar bill or 3 at the pool bar every day and a few at each meal seem, to us, to be appreciated and make a difference. I actually bring a stack of singles with me every trip for this. Again, YMMV.