[Caden]

Uncanny dodge gives you a dex bonus when attacked by camouflaged enemies, which I think is just about useless. It also raises your saving throws against all grenades. This is more likely to affect ranged characters, since enemies throw less grenades when in melee range. The scout does have better features than the scoundrel, which can be used to raise his defenses or vitality. The scout also has the best saving throws of the beginning classes.

Scoundrel's luck raises your defense. Defense helps when people attack you with blasters and melee weapons. As a jedi, you should be deflecting blaster bolts with your lightsaber except when stunned. So defense should really only matter for your melee combat. You should become a sentinel if you're making a defensive character, so you don't get stunned or feared. If you choose the scoundrel class to get scoundrel's luck, you will only get +4 defense, but you will also get the sucky vitality points of the scoundrel and miss out on a lot of features. I don't think it's worth it if what you're building is a defensive character.

If you're building a defensive character, meaning you're not focusing on offense, only defense, then you should already have high saving throws and defense from equipment, features, and force powers (like force armor) and shouldn't worry about needing scoundrel's luck or uncanny dodge.

If your building an all out defensive tank, then I might suggest the soldier. Between it's features and life bonus, the soldier seems to be built to take damage. The soldier really doesn't do anything else, like skills.

The scout and scoundrel are both given the option of skills to avoid combat all together. However, the scout is more defensive with better saving throws, features, and life. Whereas, the scoundrel is more offensive with sneak attack.

For your defensive character I would recommend the soldier/sentinel combination or the scout/sentinel. The sentinel's stun immunity is invaluable to a defensive character, and while the guardian may have more life points, the sentinel has more force points to cast heal. Those extra force points can also be used to cast stun and force push more often, which futher reduces the damage you take.

"Flat footedness" probably would be good in the D&D world, but what works in Kotor isn't always what works in D&D and vice versa. Otherwise, I might consider the Scout to be more defensive than the soldier.

Also, A HUGE WARNING!!!!!! Don't start with 18 dex. This will signifigantly screw you over. Notice on armor how it says things like "+8 from dex"? This means that if you wear this armor, you are only allowed to have 8 modifiers from dexterity. A dex modifier raises your defense by one. With 26 dexterity, you will have 8 dex modifiers and it will raise your defense by 8 points. Even if you have 30 dex, this armor won't let your dexterity raise your defense past that 8 points. So only raise your dex to 26 and no further. You can easily get 5 dex from casting Master Valor with one of your teammates. And you can get another 5 dex just from leveling. There are also plenty of items that give you a lot of dex. I did the math once, you can get a total of 42 dex on the Xbox version. So look into those dex raising items, along with items that raise your saving throws. Focus on raising your constitution after you have 26 dex, as this will help your defensive tank character.