Your 2014 Targets:

[AmericanNation]

Republicans certainly don't have as much room for growth.

I'm guessing Arkansas has term-limits, so that'd be a nice pickup. I think the GOP may pick up another seat or two, probably in the Northeast.

Gubernatorial races are very hard to predict this far out, as the economy is a huge factor, as well as who the President is. Republicans could gain 4 or 5 more seats, or Democrats would win 12 or so.

If Republicans gained four or five more seats, the Democrats would be down to a record low 11 or 12 seats out of 50. 

Democrats may trend near that historic low.  A 10 to 15 state party will naturally have problems winning 25 governor-ships.  Although it is possible, but not likely.  Financial problems in traditionally blue states will continue to produce GOP governors as democrats refuse to confront math.         
The Senate should also trend this way, but it hasn't.  I'm guessing that because a Senator doesn't actually have to do anything, is why democrats fair better.     

[AmericanNation]

Republicans certainly don't have as much room for growth.

I'm guessing Arkansas has term-limits, so that'd be a nice pickup. I think the GOP may pick up another seat or two, probably in the Northeast.

Gubernatorial races are very hard to predict this far out, as the economy is a huge factor, as well as who the President is. Republicans could gain 4 or 5 more seats, or Democrats would win 12 or so.

If Republicans gained four or five more seats, the Democrats would be down to a record low 11 or 12 seats out of 50. 

Democrats may trend near that historic low.  A 10 to 15 state party will naturally have problems winning 25 governor-ships.  Although it is possible, but not likely.  Financial problems in traditionally blue states will continue to produce GOP governors as democrats refuse to confront math.         
The Senate should also trend this way, but it hasn't.  I'm guessing that because a Senator doesn't actually have to do anything, is why democrats fair better.     

Democrats also have a better history of nominating decent candidates. I hate saying this, but I sometimes wish we nominated Senate candidates at the state convention. We would have most likely won in Nevada, Colorado, and Delaware if so, putting us at 50 seats. That being the case, there would be no doubt the GOP would take the Senate in 2012.

A state convention can officially endorse a candidate for the primary, so maybe that could be looked at as more of a king-making process.  It typically requires about a 75% vote of official delegates?  Of course the people at the convention would have to get more serious and the primary voters would have to react accordingly. 

In 2010 , Wisconsin's convention shocked people by endorsing Walker over Mark Neumann.  It was surprising given that at the time the primary was perhaps 55/45 or even 50/50.  So, clearing a 75% threshold means something.  Ron Johnson was also endorsed despite being an unknown and he only declared his candidacy the week before. 

So I think you are right that state conventions can play a role in states that have their acts together.  Candidate recruitment is most important.  I always like selling something that sells itself.