Methane reflects a much higher percentage of IR light back at earth relative to CO2, making it a much more potent greenhouse gas. So all things equal, it is better to burn it than leak it. Some cattle farms actually do this, capturing the cow farts to burn. It’s still primarily a fossil fuel though; the rocket industry is so niche it’s not really an issue, but long term huge consumers like national energy grids will not be able to rely on it (aka natural gas, a neat marketing ploy ;) )

Depending on the contractor they may get government benefits too. A friend of mine worked for Applied Physics Lab and got government holidays, 10% 401k match, vacation banking etc.

The atmosphere is extremely thin, less than .01 Bars at dust level, and also extremely cold. No runaway greenhouse effect, quite the opposite in fact. The atmosphere has been blown off and almost all heat radiates away into space.