aren't Full Thrust, Drain Blade, etc considered Techniques?
anyway, I was really surprised that I only experienced one half of the battle system too.
also, lets not forget that each Phantom Sword comes with a new mechanic, like Warp, Knightsguard, etc... will probably get a total of 8-10 of those swords on the final game and just imagine how many things we'll be able to do.
Sorry if any of this is a little disjointed, I moved parts around and didn't want to restructure my entire post.
No, they are abilities tied to a specific weapon. Techniques are part of character growth, hence why you get them through leveling up. The camp menu makes a clear distinction between Ability and Technique in the English menus at least. The Japanese menu does say on the camp screen ability and not Technique", but the English version does say Technique so I'd like to believe they are different. I haven't forgot about the Phantom Swords, however these don't facilitate the need for a specific section in the level up menu solely for an abilities list for when leveling up. There has to be something that is tied into this window when leveling up.
Ignis for example has the ability "Cure" which isn't bound to his weapon in any way, which you could argue might not be a technique at all, but rather an ability. Then you have Gladio and Prompto who both have one ability/technique that they use which you might say is weapon bound. I don't think this is the case however, considering these guys can only have one weapon at a time, it would make their versatility in combat extremely limited. I'm going to assume that characters have weapon skills as well as character bound abilities, perhaps similar to Type-0 in execution.
It doesn't make sense to me to only gain abilities through weapons, the window in the level up screen wouldn't make any sense at all if they were only tied to weapons. Some character growth in terms of your abilities needs to happen, and of course it wouldn't make sense to gain abilities based on what weapon you have equipped, because then that would suggest your weapon needs to level up? The weapons have tiers on them already, indicating what rank they are in strengths against each other. The ability description for the weaker lance (forgot the name) in the Japanese text basically says that it's a weak spear but makes up for it with the critical hit rate boost. To me, this suggests that the tiers are essentially a way to classify a weapon's rank against other weapons, not a means to increase its performance.
We have yet to see Noctis execute moves shown in the E3 demo like dodge roll or the polearm/spear spin, nor have we seen moves like jumping over enemies or slamming them into car doors or other obstructions. Tabata did say that everything in the E3 demo besides characters switching will be in the game, and while perhaps things like car door slamming is contextual to the environment, certainly the polearm/spear spin move and dodge rolling is something that isn't contextual to an environment.
tl;dr - We wouldn't have a techniques window in the level up screen if all we had was weapon skills.