You say that you used Titebond thick adhesive but I am not sure what that is.
Titebond make a wide range of adhesives from wood glues through to caulks and sealants so without knowing the exact product I cannot say whether I would recommend it or not.
If you mean this then I have not tried it but from the description it should do the job but you might find the short open time to be a problem.
As Brian says there are plenty of adhesives that will work, don't let anyone tell you you must use one or the other.
Cyanoacrylate superglue (CA) will do the job fine, either thick or medium is probably best. The only problem you might have (as you already know) is that it has a short open time so if the drilled hole in the blank is tight or you take too long getting the tube into the hole you might end up with a half glued in tube. Very irritating but avoidable with care.
Two part epoxies such as Araldite are also good and give you longer to get the tube fitted . The downside is that you have to wait for them to set before you can get on with the turning.
Polyurethane glues such as gorrila glue or titebond polyurethane give a good bond and are effective gap fillers but because the glue expands as it sets it can push the tubes out of the blank unless you clamp them.
My personal preference is for a quick setting epoxy which gives a good bond, has a reasonable open time to get the fit right, has some gap filling properties and doesn't take too long to set.
Edit: Sorry, got carried away with the pros and cons of glues and forgot to mention the pens. They all look good to me. Your pen making course served you well.
