Yes, there is a risk of being sued for negligence in not clearing the brand names you recommend. You can provide a disclaimer to reduce this risk, but not eliminate it. I would strongly suggest you at least do both a basic TESS search and Google search for conflicts, as I would consider it negligence not to do so. Plus, you don't want to waste your time working on marks that are surely blocked legally.
if you don't know how to do those searches then you need to consult a trademark attorney. The same is true for logos or designs if you provide them, also.
I provide these services for clients and offer free initial consultations, as do my colleagues here on Avvo.
I am not your lawyer and you are not my client. Free advice here is without recourse and any reliance thereupon is at your sole risk. This is done without compensation as a free public service. I am licensed in IL, MO, TX and I am a Reg. Pat. Atty. so advice in any other jurisdiction is strictly general advice and should be confirmed with an attorney licensed in that jurisdiction.
"Is there any problem with this?" You risk angering your customers.
A disclaimer stating that names you have come up with may not be suitable for business and that customer should verify suitability before using, would give you a point to argue if they sue you, but it would not guarantee you would win a lawsuit filed by a customer to reclaim the fee they paid you.
It may be a good idea to collaborate with a trademark search service provider to provide the names that are cleared through a search, for example, http://www.cardinal-ip.com/products-and-services/trademark-searches/.
This is not a legal advice or solicitation, and does not create an attorney-client relationship. Consult with an attorney. I work for Cardinal Risk Mangement and Cardinal Intellectual Property, IP service companies, but not law firms. I also am the president of Vepachedu Educational Foundation Inc., which is a non profit educational foundation. I also write cultural and scientific compliations for the foundation. I also teach at Northwestern university as a guest lecturer. I also provide some pro-bono guidance on immigration and other issues through Indian American Bar Association. I also have a contract with Cardinal Law Group, a law firm, for IP projects. All this information is on my profile at Avvo and also at Linkedin. Any views/opinions expressed in any context are my personal views in individual capacity only, and do not represent the views and opinions of any firm, client, or anyone else, and is not sponsored or endorsed by them in any way.