Probably the only reason to attend A PG Showcase (Underclass) would be if he is truly a top level player.
I'm only speaking about our events... If he is truly a top level player, he will be identified as such and those in the scouting world will know who he is. Granted this doesn't pertain to MLB scouts or college recruiters as much as it does for others who recruit the top players. That would be highest level travel teams, USA Baseball, etc.
Yes, there are many national level travel teams that recruit players outside their area. Yes, there really is a USA 14 year old national team, as well as 16U. Players that wait until they are 17 or who don't live in a certain area of the country, need to be identified in order to get these opportunities. That's if those opportunities are even important to a person. If they haven't heard of you, the opportunity isn't there.
If a player is outstanding... Don't ever be fooled into thinking being identified early is a bad thing. There is a very long list of MLB players and first round picks out there that actually benefited by being identified at a young age.
All that said... For the vast majority of young players, even those who are talented... There is no real hurry or necessity. I would agree on spending money getting quality instruction and/or attending college camps. Make sure it is "quality" instruction. Also get on a team, as good a team as you can and play against the best possible competition.
Also, are you sure about that 1.8 pop time? If so, that is unreal for a 14 year old. So is the consistently under 2.0, for that matter.