The answer is simple. RPG Recruitment will represent you to clients better as they will already have met you and will already have a very good understanding of what type of candidate their client is looking for.
Your CV is very important in your job search. A good CV can be the difference between getting an interview for a role or being immediately placed on the regret file. You need to ensure it represents all your experience in a clear and concise manner. Put time into getting the CV right, you may need to find professional help on this.
Preparation for any interview is vital. As a candidate you must know your CV well, no hesitation on dates etc.. as not knowing your CV will give the employer the impression that you have not (a) prepared your own CV (b) have fabricated some areas on the CV. You must read the job specification carefully and ensure you have the experience readily available in your head where you have demonstrated you can carry out particular tasks. And finally, research the company, the Interviewer will expect you will have done this, not doing research will give the impression that you are not overly interested in the role.
You are probably looking to change for career progression, and this is perfectly okay to say in an interview.
It is ok to tell the interviewer what your current salary is and if they ask you for your salary expectations, it is also ok to disclose this. However do not get into a negotiating situation with the Interviewer as this is still an interview situation not a job offering situation.
At first round interview it is essential you have prepared a couple of questions to ask. This shows the interviewer your level of interest in the role and the company
You can ask as many questions as you like in the interview but only towards the end of the interview. Up to this point you need to concentrate on selling your skills. Typically candidates will ask 2 or 3 questions