1. Depends on the registry. Some, like the Hanoverians, require both parents to be in the studbook in order for the horse to be registrable. Some allow you to pile any 'ol horse off the trailer, run it around and as long as it gets a decent score it's accepted. The first type of registries are generally considered more prestigious and the horses in those registries are valued higher.
2. Like anything else - you can have a well bred really nice horse but if it's not broke it's a pasture pet.
3. A sport horse is a horse bred for English sport and can encompass a number of breeds outside of the warmblood family. There are sport horse registries and they will register your horse if it runs around and gets a decent score in an inspection, although they are usually less rigorous than at a warmblood inspection.
4. Depends on the horse. Most are so expensive that it wouldn't be frugal to have them on a ranch. $40,000 is a little pricey in that application...
5. Depends on the horse. What you can expect from a well bred, registered horse temperament wise is not a beginners horse but many are well suited to the application as an amateurs horse. They tend to be spookier, flightier, more headstrong and athletic than your typical horse.
6. For me? I look for an uphill balance in the horse, a shorter underline than top line, a well set neck, good hindquarters, average length back and excellent legs. Arguably the most important thing in looking at any young horse is to look at the movement and the tendencies in it. The younger the horse, the less emphasis you can place on conformation. The skill of picking up on a good horse while it is young is very hard to develop and well sought after.
Post pictures! Oh I love babies!