Bruh, I can tell that you have some knowledge on the topic, but the idea that Superman doesn't use his speed when fighting his villians is just untrue. I can provide countless examples that prove he does. Just off the top, in a 10 second search...
1.
http://static.comicvine.com/uploads/original/5/54191/2712779-2374115_1630908_superman_phasing.png
2.
http://static.comicvine.com/uploads/original/5/54191/2712780-2374123_doomsdayrex118xm.jpg
3.
http://static.comicvine.com/uploads/original/5/54191/2712781-2374128_robotkz6.jpg
4.
http://static.comicvine.com/uploads/original/5/54191/2712782-2374129_sm21013tk0.jpg
5.
http://static.comicvine.com/uploads/original/5/54191/2712783-2374131_supermanv2172pg13.jpg
6.
http://static.comicvine.com/uploads...84-2374136_week01_2000_superman_v2_152_04.jpg
The KEY POINT about this is that Superman holds back and only really uses his speed when he needs to or when he is fighting an opponent that has superspeed as well. Against a fast fighter like Goku, he will take notice of his speed and adjust accordingly.
Regarding Goku's method of attack, personally I DO believe Goku has planet busting power, but he has never actually done that feat before. How he would actually bust a planet is up for debate but nobody in DBZ Pre-BotGs has ever busted a planet physically, thus I don't believe they are capable of it from any time pre Buu saga. And him teleporting and using a Kamehameha can work on some, but its not going to stop the upper tier villians Superman deals with and it'd take a very focused attack for him to do this without blowing up the planet and killing himself. He'd have to do what he did to Cell and land a direct attack and if he does that to Mongul, Doomsday, Brainiac, Atlas or the upper tier guys, they are all fast enough to react to him and possibly counter. Goku vs. the Upper tier of Superman's villians is a tough battle in any means.