Paul Seiter

I'm hoping somebody will respond to this question. I recently purchased the Husqvarna 12527 HVX, which I believe is Lowes modified version of the Husqvarna 12527 HV.  It snowed the next day, and when I went to start it up, I noticed that there wasn't an On/Off switch, or a throttle engine control speed. The manual had suggested otherwise. The engine on this model is the Briggs and stratton 250cc. I began to google this particular model of engine and every picture shows this engine with a throttle control speed and an On/Off switch. I'm no expert when it comes to engines, but I was under the impression that it isn't good to cut your engine at full throttle (which apparently can only be done by pulling the safety ignition key out, because there is no on/off switch). I'm looking for some peace of mind here, as I've only had the machine for 3 days. Do I need to worry about this, or is it just fine to cut your engine this way. It just seems standard to have some type of throttle control. Please respond to this question, answering why there isn't a throttle control, as well as an on/off switch. I would like to know the disadvantages as well to this. 

Thanks in advance!