But I have always thought that no matter the reaction liquid is optimal because solids don't react unless it is oxidation or dissolving
This is incorrect, or at best, an issue of semantics -- so what if a solid and gas reacting is an oxidation, its still a chemical reaction. What reaction, have you mentioned, is not ultimately reducible to a red-o reaction and explicitly excludes solid reactants?
and gases have little time to react because they move so fast.
Likewise false. Many gaseous reactions are very important -- reacting nitrogen and hydrogen to make ammonia is a critical industrial process. Reactions of chlorofluorocarbons with traces of ozone in the upper atmosphere are very significant.
Plus standard pressure is I think best if you want to carry this out in the liquid state
OK, I accept this premise ...
because pressure often increases temperature
Excellent, a valid application if gas laws, an important chemical concept.
if you add it and decreases if you subtract it so the reactants at low pressure, almost a vacuum will be solid but at high pressure be a gas.
This is not as good an application of the gas laws. You have inverted the behavior of substances with low vapor pressures, and the statement is not apt for other situations.
Temp is much easier to change without affecting pressure than pressure is without affecting temp.
I'm sad to say, you are mis-applying the gas laws, which you had applied well before. There is a proportional, reciprocal relationship between temperature and pressure.
That is why liquid at standard pressure is optimal for reactions.
Regrettably, you are not providing support for this hypothesis of yours.
As for starting the reaction liquid chlorine could just touch a methane molecule that is also liquid and grab that hydrogen and the other chlorine bonding to the methyl that is left without irradiation because liquids more often touch the right way than gases do.
Not an apt statement.