Perhaps emailing the Yaesu and Icom importer or main dealer would be the best way to get figures of rise or falls in sales of SW radios - thats IF they would tell you. In general though popularity of SW has dropped with each step of introduction of m...
The only way you can get secure transmissions from any radio is to use digital encryption. Any clear modulation can be heard regardless of the band or frequency you use. And yes, you would need a license for a 5 watt radio.
where in the world are you? if in the UK, its a wonder the thing hasn't blown up! if in the USA - look on the back of the radio you are powering from the adapter and look at it's power consumption it will say something like " input 12VDC 900mW" or 75...