1. I didn't notice any bikes for hire at the hotel. There was a place in Tamraght, the next village closer to Agadir, that was advertising bike hire at 50 dh/day. To be honest, the boardwalk is only just long enough for a cycle ride, and I wouldn't want to cycle on the roads - although we saw a few hardy long range bikers elsewhere on our trip, including one on a recumbent and one towing a surfboard!
2. this was part of our larger self-drive Morocco road trip flying into Marrakech, so I don't know about Agadir airport, sorry. Taxis should be relatively cheap, Marrakech airport has a fixed price taxi system so no haggling and no hassle, not sure about Agadir. If you were to drive, driving in Morocco is straightforward with good roads and little traffic, apart from in the city centres which can be mayhem. Always stop at the (frequent) police roadblocks, as a tourist 98% of the time you'll be waved through, the other 2% they just want to check your car papers and driving licence. Police-operated speed cameras are common and well hidden, so drive conservatively to avoid a debate about a fine...