In a couple of posts on the official Star Wars: The Old Republic forums (here and here), principal lead systems designer Damion Schubert adressed some of the concerns the community has had about the free-to-play systems and their effect on the game's balance. Here's a couple of snips:
We've been observing PTS closely over the last few days. In that time, we have generally been very pleased with how well the build has been performing, as well as overall reaction to the build both on the boards and in-game. That being said, based on community and internal feedback here and further deliberation, we will in short order make the following changes to the Free to Play restrictions:
Free-to-Play players will now get a second quickslot bar.
Free-to-Play players will now be able to do 5 Warzones per week instead of 3.
The Cartel Coin item lock (i.e. temporary bind) will be reduced to 3 days for Free-to-Play players, and 2 days for subscribers.
Perhaps the most interesting point regarding the Warzones limitation is that some players have concerns that putting limitations on Warzone runs might make Warzone queues less likely to fire. While it is possible that this may happen, we don't think it will -- our subscriber base likely will not shrink much, and for some of our competitors, converting to Free-to-Play has resulted in a subscriber increase! Which means that Warzone queues should likely see improvement from what you experience in game, and at minimum be relatively unchanged in experience.
That being said, one of our golden rules is that the Free-to-Play experience should not cheapen the experience for paying subscribers. If it turns out that the Free-to-Play conversion results in a degraded Warzone experience once we go live for subscribers, you can rest assured that we will quickly make adjustments to the system to ensure that subscribers have an optimal experience.
Currently, these crystals appear in cartel packs with a level 10 requirement, and on the store with a level 35 requirement, in order to access stats roughly equal to a standard level 50 color crystal. It's worth noting that color crystals are something that the itemization team stopped improving the itemization of shortly after launch, because people really hated losing their signature lightsaber color because it was no longer Best in Slot. We have, incidentally, seriously entertained removing all itemization from color crystals entirely (it makes many problems go away for us), but we didn't have the time to make such a large change on itemization before this patch went live.
The reason why we put these in with low level requirement is pretty simple: getting an item you can't use in the Cartel Packs really sucks. It's the same reason we pursued the tech that allowed us to make mounts adaptive - we expect a very large influx of new players when we launch free to play, and those guys opening cartel packs to get items they can't use for months (literally, for casual players!) is a negative experience, not a positive one.
The net result of all of this is that slapping one of these color crystals in your saber at level 10 effectively makes levelling from levels 10 up somewhat easier, with the benefits tapering off quickly as the player levels up, and eventually zeroing out altogether. We felt, in general, that that was okay. The focus groups that we ran also seemed to think it was okay, as long as we avoided endgame power.