To answer your question:
Yes, you need a PSU... Here's a thread with PSU discussion: https://bitcointalk.org/index.php?topic=1177795.0. Or you can buy a bitmain PSU just to be sure: https://www.amazon.com/AntMiner-APW3-12-1600-Supply-Bitcoin-Miners/dp/B013WW2YWE

No, the ASIC can ONLY be used for sha256 crypto currency mining.
Next to bitcoin, you could also use it to mine other coins from this list: http://www.coinwarz.com/miningprofitability/sha-256 (list is not complete). You cannot use an ASIC to do anything else. You can't even use your asic to mine non-sha256 coins (for example, a bitcoin ASIC can not be used to mine litecoin)

Your main question, however, should be: can you mine with profit??? This mostly depends on your electricity rate, but also on your custom rate, the shipping costs, the fact if you have coupons, wether or not you have a cooled room with strong shelves, wether or not your electrical wiring is OK to plug in miners, wether or not you have enough time and technical knowledge to run a miner, your luck,...

In 90% of the cases, bitcoin mining will NOT be profitable...