Once you unlock the Devidian series, the game improves quite a bit. I have to say though, that I think a substantial number of players will have left well before then (even if the T1 powerleveling curve we're enjoying on Tribble goes into production).
LTC starts to be good because you can actually get decent gear just from replay missions, which is really nice; I always liked about STO that you could get everything you need just by playing the game.
LT is really, really bad because there is nothing in that range that you can do to get more than a couple Mk II items. This rank is sorely hurting for its own gear-rich mini featured episode series; basically an LT level Devidian arc that you can access right from LT1 to get green Mk II ship and crew weapons and shields, at least. This is the biggest gap between the crucial first levels and LTC at this point; as it is now, LT is defined by getting gear that is obsolete the minute you pick it up, whereas at LTC you can get Mk IV equipment right from the start. That approach should extend through all the levels, not just from 11 on up.
Also, the Miranda really, really needs some help. It is far too slow and weak, and when you're hobbled with Mk I gear at LT9, it's downright painful. Even full impulse feels like swimming through cheese in this ship. Seriously, this little rowboat is single-handedly going to cull your F2P playerbase by 50% before they even see their first T2 ship. It's that bad.
And you have to do something about the experience of staring at a black screen for 20 minutes. This is intolerable as a defining element of the game for new players. You really have three choices here: (1) double or triple baseline warp speed across the board, for everyone; (2) make some amazingly beautiful spacescapes for sector space; or (3) keep ALL the missions in Vulcan sector and DV through LTC. Actually you have a fourth option as well, which is just shrinking the entire map to 1/2 it's current size in all dimensions. None of these other than (1) seem like something that you could actually do in a reasonable time. But something has to be done.
Even at LTC, warp travel is still unreasonably tedious and boring. But at least once you hit LTC most of your missions within the tier tend to be within the same sector block. It's ironic that you force people to do more running around at LT than at higher ranks just to progress through the pre-set storylines.
Seriously, staring at a black screen for 1/2 to 2/3 of your time in-game is going to cause F2P players to just sign off before they ever get to anything good. Keep in mind, there is right now basically no way to get around this until you get to the STFs or grind to Ambassador (which I haven't even figured out yet, since it looks like now diplomacy is tied into the DOFF system). The game has so much great content, but a LOT of new players are going to leave before they ever see it, because they get sick of sitting there staring into the void.