The pulse tech Tree has no need to be researched, until you play very particular counter strategies (ie carrier spamming, sending 20-30 skirmishers to take out the carriers) or very lately in large games. Even when you get RA up (if you go for it), it is often better to scuttle the skirmishers, since you'll get so many carriers (and flak), getting the control of the sky wont be a real problem.
And, as you point it, Vasari's main weap is the phase missile. Flak use phase missiles. Strikecrafts use phase missiles. Most caps use phase missiles. Assaillant use phase missiles. Even turrets use phase missiles. So it is very cost effective to research phase missiles, much more effective than pulse tech line.
As for bombardement range increase, it is like a goodie, since if you send bombers it often means that you have total (or almost achieved) control of space around the planet.
