Sometimes one faces a situation like what you are facing now.
Salary, job security, job satisfaction, job enrichment etc may be at loggerheads at times.
You need to make a decision about your priority.
Enrich your knowledge by studying books, follow the latest trends, read good articles and thus keep yourself active and updated. Opportunities will come.
There is very little you can do to change your bosses. Have patience.
If you feel you are being diverted to admin, just do the work given while biding time for change of job.
Spend time reading abut trends and issues of HR,and get updated.
Volunteer for extra jobs of HR even if you are being pushed into pushed, in admin roles.
Future is always unpredictable, no point worrying about future.never hesitate to ask the salary your qualifications, experience is getting normally across other companies and industries.
These kind of issues creep up in every working professional's life.
They need to be faced as per circumstances.
By doing admin work you can show your skills to employer and he will also develop a trust and confidence in you.