Advocate or lawyer

I have no doubt that there will be some estate agents who offer "additional services" which they may not be best placed to offer advice/guidance on but will seek to do so in order to increase their fees. This applies not just to estate agents but to a range of professional services firms. It also applies as much in the UK as it does in Spain as each country does not protect people from claiming to be X, Y or Z without any qualifications.

Around where we are, you will often see shop front banners stating "Lawyer" - no doubt a term most English speaking people will assume come with a requirement for qualifications, professional body registration and associated insurance etc. However, I don't believe that to be the case because the "protected" term in Spain is "Abogado" and you should ensure that if seeking legal advice they are appropriately registered with the regional bar association / national body.

In the UK (and I think in Spain), the term accountant and equivalent is not protected so anyone can call themself one or put it on a shop front etc. 

The key thing I would say, is that when you know what services you require then ask for personal recommendations etc from friends and neighbours/residents. They would likely be much more independent in offering advice than an estate agent. You might pay more for using services independent of the estate agent but that extra peace of mind and protection could be potentially priceless if anything were to go wrong.

A so called "asesor fiscal" is cheaper than a lawyer. There are plenty of them so pick the cheapest.