Derek, the problem with your post is that you've given us a series of graphs, whose origins are unknown, that seem to show a correlation between GCRs and some climate parameters. It's simply not possible to answer your questions based on this. Could you please post the links to the papers from which these graphs come?
I'll try and answer your questions looking at what the scientific literature says, though I'll start with a simple observation: in 2009, cosmic ray intensities were about 19% higher than any observation in the past 50 years (see NASA graph below), so if they had a major impact on global temperatures, why have these not dropped? We find ourselves in a situation where natural factors - deep solar minimum, one of the strongest La Niρa on records - would lead to a cooling, yet temperature records show no dip in temperature.
Three steps are required for GCRs to seed clouds:
1.
GCRs must induce aerosol formation - this is not controversial and is shown in lab conditions.
2.
The aerosols must grow sufficiently (by a factor of about 100,000) to form cloud condensation nuclei (CCN) - this is where the problems start.
Pierce and Adams (2009) find that
In our simulations, changes in CCN from changes in cosmic rays during a solar cycle are two orders of magnitude too small to account for the observed changes in cloud properties; consequently, we conclude that the hypothesized effect is too small to play a significant role in current climate change.
3.
CCN must lead to increased cloud formation - research shows that GCRs are not effective in cloud formation.
Kazil et al. find that:
the variation of ionization by galactic cosmic rays over the decadal solar cycle does not entail a response...that would explain observed variations in global cloud cover.
And
We estimate that the variation in radiative forcing resulting from a response of clouds to the change in galactic cosmic ray ionization and subsequent aerosol production over the decadal solar cycle is smaller than the concurrent variation of total solar irradiance.
Sloan and Wolfendale (2008) estimate that:
less than 23%, at the 95% confidence level, of the 11-year cycle changes in the globally averaged cloud cover observed in solar cycle 22 is due to the change in the rate of ionization from the solar modulation of cosmic rays.
Kristjansson et al. (2008) find:
no statistically significant correlations were found between any of the four cloud parameters and GCR
Kulmala et al. (2010) conclude that:
galactic cosmic rays appear to play a minor role for atmospheric aerosol formation events, and so for the connected aerosol-climate effects as well.
The evidence for a major role of GCRs on the climate is not there - since the assertion is that GCRs impact climate through low-level cloud formation, the findings that GCRs only play a minor role in such cloud formation suggest that GCRs are not a main driver. Wouldn't you agree?