I’ll probably get flamed for saying this, but you won’t be happy with the little Ninjette on the freeway. You will have it screaming at 8,000 RPM keeping up with freeway traffic. If I had to pick among your other choices for your intended use and experience I’d go for the Ninja 500. It has plenty of power for freeway cruising, but not so much that it will get a beginner in trouble. The SV650 is a good bike too bike, but the extra power may be too much for someone new to motorcycles. I’d scratch the Bandit 600 and GS500F from your list because it is air cooled and the maintenance, if you follow the factory schedule, will be much more expensive than the Ninja 500. Valve adjustments alone will negate any fuel savings.
If $3,000 is your budget I’d suggest you start buying gear now. There are plenty of threads here on riding gear. If you look around and buy closeouts from online retailers (newenough.com is excellent) you can get good gloves, helmet, jacket and pants for $500. Don’t forget eBay. I just got a pair of like-new Held gloves for $60 including shipping. Not bad for a pair of gloves that retailed for $280.