The answer is yes on both counts
Enjoy your holiday
Yes the Falls are always open and the Capercaillie is open on Christmas Day too not sure if you'd need to book though
yes its free and open all year to view although local hotels may be closed
Wring 01567820355 which is a local restaurant in Killin and they will surely tell you
Wring 01567820355 which is the local restaurant The Capercaillie in Killin and they will surely tell you
Get quick answers from Dochart Falls staff and past visitors.