thank for reply, about the optios that you have, i agree whit the mentioned by dancingmolly and those are the most confortable option that you have in the park but probably not the best locations to visit the most intresting places as you want to take pictures, so let me give you the other side of the options that you have and also qhere your parents will enjoy at the same time maybe doing short walk at the same time that you hike to the look out points...:
1) trere is a company tath runs regular tour from calafate to torres del paine national park and give you the chance to stay in the park and returns another day if you want it.
check this link: ( is the direct link to the information about the trips to torres del paine national park )
there is a link for contact and ask futher information.
2) dancingmolly gave you the options in hotels, probably is the most confortable option for your parents. but for example: you can stay at the Refugio Torre Central at the same location of the hosteria las torres but for a cheaper price sharing room and bathrooms but with new and clean facilities and good food.this gave the option to walk to the towwer look out point and probably your parents can take and excursion or if the want to try the towwer probably the best options for then is to take horses from the hotel up to the refugio chileno and then you can continue to the walk.
this is the contact of the company:
then to visit the french valley and grey glacier you can arrange a tranfer from hotel las torres. fantastico sur and hotel las torres are the same company you just at the reception of the refugio you can do this bokking. ok.... sao take a tranfer to pudeto to take the catamaran hielos patagonico and cross the pehoe lake to arrive to the Paine Grande Lodge. is a huge refugio with excelent facilities and the same conditions of the torres central refugio (cheaper price sharing room and bathrooms but with new and clean facilities and good food.)
the company is :
from these refugios you have the options to walk to the most interesting places of the W in the park adn your parents can try the same walk a maybe closer walk aourd the area..anyway the wiew from this places area really good
the company of the tour from el calafate ( chalten travel) can leave at the entrace of the park to take a trafer and go to the refugio torres central or if you want to stay at the paine grande lodge the same tour take there too...
check the information and contact then for bokking information.. and also you can rent the sleeping bag in the refugios..so you don need to carry in..
good luck and i hope to give a hand with this information