would a handheld digital FHSS radio with a transmitting output of one watt work with this amp (TSWL466625) or is that too much input power
Yes that would be too much input power. Maximum input power is limited to 20dBm (100mW) so a 30dBm input would be outside the amplifiers dynamic range.

You may use an attenuator which if you combined with port converters (to convert from SMA to N type) would bring your input power level to within the range of the amplifier.