So, speaking as someone who's played a fair amount of sins but hasn't really gotten into multiplayer, would you say starbases are not effective at slowing the enemy while you obtain HCs when you have a chokepoint world? Also, how effective are fighters against LRFs now?
Starbases are useful for protecting your fleet and structures, but not for stopping the enemy from advancing and/or attacking your planet if they really want to. Unlike the AI, only very stupid humans would charge headfirst into a starbase. A starbase is also a pretty big investment - getting one up is quite costly, almost as much as building military structures and researching HCs I think. It'd probably be better to invest in a fleet, early-mid game at least... except if you're Vasari, in which case having a (moving) SB could be somewhat more useful.
While fighers can do a good amount of damage against enemy LRF, especially if the fighters hold position, they're also ridiculously easy to counter with flak, which completely melts fighters. If you're playing a competitive MP game and haven't had spare resources to get HCs going, it's definitely better to counter enemy LRF with your own flak or LRF.