A dynamic seismic analysis is not something that should be performed without guidance. Is there someone there that can help you, and review your work (and assumptions)?

The "Frequency Cut-off" is the frequency at which you're telling the solver to stop extracting eigen-values (natural frequencies) and eigen-vectors (mode shapes). For a seismic analysis this cut-off is usually 33hz (because all the energy in an earthquake is below this value). CAESAR II will solve for one frequency above your cut-off (it has to detect that it passed the cut-off).

The "Damping Ratio" should be left alone. You can read the "help text" on this item (press [F1]) for more information. I wouldn't change this unless you have a really really really good reason.

The "Max No of Eignevalues Calculated" (which I believe you refer to as the "Nº of frequencies" is just that - the maximum number of eigen-values extracted. This is an entry you should leave as zero - unless you're dealing with an academic problem. In a realy system you don't know how many frequencies to extract, so it is better to deal with the cut-off value.

The CAESAR II eigen-solver stops at whatever comes first, either the frequency cut-off or the maximum number of frequencies. If you solved for 100 frequencies, and your maximum was only 1.1 hz, you have a very flexible system - probably way too flexible. I recommend you recheck your input (both the model and the dynamic input) to make sure everything makes sense.

For the "relief" issue, check out the RELIEF example problem. You can find this in \caesar\examples.