hybrid airebo lj parameters

Hello, guys
    I have a question about airebo potential. I want to simulate toluene in water. If I use airebo potential for toluene, I need to specify the lj parameters between toluene and water. The airebo potential file gives the epsilon and sigma for C and H atom.
    My question is that, should I use the same epsilon and sigma from airebo potential file for every C and H atom in toluene?

no.

    But in chemistry, the C and H atom in the methyl and the C and H atom in the benzene should not be treated the same. However, there is only one epsilon and sigma for C and H atom in airebo potential file.
    Can anyone give me some explanations?

AIREBO uses a very different parameterization strategy than what you
will have to use for the toluene/water interactions, so you cannot
really compare those.

is there a particular reason, why you need to use AIREBO? in my
personal opinion, a better approach would be to use a consistent force
field for the whole system, e.g. OPLS/AA. then there are no
ambiguities and inconsistent parameterization methods.

axel.