is there a way to lube the choke cable to make it easy to pull??
Same as any other cable... you likely will have to remove it . I haven't messed with mine... actually, never used it... so I don't know if you have to take it completely off the bike. Check the linkages first. I think they are normally stiff.
I use mine during cold weather riding 34-45 degrees. It is stiff when you pull it out. I only need to use it for about 1 minute before I push it back in.