1) Is/Will the suggested appointment time, date and location workable for you? If not, please specify a new time, date and location that is workable for you.
Can I use workable in the sentence? Does the sentence need any correction?
Is [it] workable - possible
Does [it] work - okay
Will [it] work - my preferred choice
I'm not a teacher, but I write for a living. Please don't ask me about 2nd conditionals, but I'm a safe bet for what reads well in (American) English.