All great questions, John, and I look forward to seeing how others will answer these questions as I am not the most experienced open-segment turner on this site, by far. First, make sure that ALL of your stock is exactly the same thickness.
Before we start, here are some thoughts on adding glue and removing glue squeeze-out. I use the new
Rockler Silicon Glue System to add glue to the segments. I put some glue in a corner of the tray and then hold it at an angle. I then use the solid end of the brush which is like a painter's wedge tool. I dip this perpendicularly to the very end of the brush and then touch it along the two edges of the segments that are on the plate in their final position. This lets you get just the right amount of glue in just the right place and minimizes squeeze-out. I have experimented with putting glue on both pieces and a single piece and have found no noticeable difference and so I now just apply glue to the pieces on the plate. Once I have added the weight, I take one Q-tip from a container that filled with water and squeeze the water out of both ends. I then slide this end through one opening and then one more opening and then flip it to the other end and do the same for the next two openings. I then return this Q-tip to the water and grab a new one.
I get all the way to where I have a few rings of the open segments together, and think this is where I should turn the inside..??
I do not recommend finish turning the inside yet as you want to leave as much glue surface intact to maintain integrity - especially of the lowest rings. Also, I don't touch the last ring added with a tool until another ring has been glued to the top of it. The new ring adds strength to the ring(s) below it and makes it stronger. It is alright if you want to turn off the corners of the rings below the top ring as you go.
My advice for tool selection is to always use a tool that will shear cut the wood as opposed to scraping it. This means a bowl gouge or the carbide disk tools like the Eliminator that will shear cut the fibers. Scrapers, if sharpened correctly, cut with a burr and depending on how you raise a burr, it can make a very aggressive cut.
I use a piece of MDF that is approximately 4" x 8" that has 120-grit sandpaper glued to it with spray adhesive and LIGHTLY sand the new ring to give a good, flat surface for adding the next ring.
So, if I did my glue up correctly, will I be able to turn the open segment rings 'before' I add any kind of normal closed ring..??
I would add closed rings after flattening the prior ring and before any finish turning This closed ring will add great strength to all the open-segment rings beneath it and you'll be able to turn all the rings as if they were all closed segment rings.
Once you start the finish turning on the inside, make sure you start from the last ring added and work toward the bottom of this part of the vessel. You still want to leave as much glue surface as possible to the lower rings to better support the upper rings.
Also, when making the o/s ornament, should the ornament be made in two halves and then glued together for final turning..??
I turn open segment vessels in two halves whenever possible. This speeds up the process greatly. I work on them simultaneoulsy. The dividing line for the two 'halves is the widest part of the vessel, wherever it falls. Once the two turnings are finish turned on the inside, add a live center with a threaded insert so that you can mount one of the turnings on the live center. Glue these two halves together while on the lathe to get perfect registration and let the glue dry.
With the two halves glued together and under pressure from the tail stock, turning the outside profile is just like turning a solid segmented piece.
I know these are simple questions...but for a newby open segment turner who is trying to really 'not' have his first o/s turning explode on him...well, would appreciate some info 
These are the questions that every one of us has had.
I am just working on a set of videos that will show the process of making an open segment vessel using the Stomper. The first video will be on designing the vessel as there are ways you can speed up the entire process and that is one of the goals of the Stomper - to let you make these vessels more quickly and accurately. I hope to have this first video done in a couple of days.
The remaining videos will be on cutting segments on both a miter saw and table saw, adding and gluing rings, flattening, turning and finally, reversing for finish work. I'm going to use a Christmas ornament as the example.
I intend to show some new ideas that I guarantee you've never seen before.
Lloyd
