How long does it take to dry?

not long at all, particularly if you use it like contact cement (thin layer on one piece, thin layer on the other...let dry and then join)>

I used it once and now I want to use it again and I can’t get it to come out of the tube?? Any suggestions please??

I just stick a straight pin in the tip or if you have a long skinny nail use that. I have to do that when I don’t put theclid on tight. I also store mine in a baggie.

How well does this work for rubber to rubber bonding?

Hi B.T. I have not used on rubber but it is great for dollhouse furniture. Wood to wood, metal to metal, metal to wood and perfect to attach wee little paper petals and leaves to tiny wires for miniature flowers. I just use a bit on the tip of a toothpick for most of the work I do. Love the stuff. Shirley Roeder

So is this capable of holding a plastic cover that hides/protects my hitch on my Chevy Tahoe that weighs around 2.5 pounds?

I've never had a problem holding items, but I"ve never used it to hold 2.5 pounds. Since there is no pressure on the cover I would think it would do the job.