I'm also trying to figure out how to switch routines, I can't figure out how...
You can't SWITCH routines. They are loaded when you start the bot, and then it will use the same routine until you close it. Should you ever need to switch to another routine, you need to restart the bot.
how does honorbuddy's dungeonbuddy/bgbuddy detect the new combat routines? do i need a plugin?
Honorbuddy detects these at startup, if they are properly installed in the Routines folder. No plugins required, or available for that. When HB detects more than 1 Routine, it will present you with a list to choose from.
Would these new routines cause you not to move/attack in Dungeonbuddy or even maybe fix the issue/bugs
Routines, in their nature are fit for different purposes. You should use Singular or FPSWare for Questing, Grinding and Farming and CLU with RaidBot or another bot for end-game Dungeons and Raids.
are these new combat routines for all levels?
You will be better off if you use each routine for the purpose it was intended for - Singular and FPSWare for Questing, Farming, Grinding and other routines for end-game content.
Typically, when it comes to Grinding, Farming and Questing, you should only change your routine if your present routine is broken, or fails miserably at too easy things, slowing down your progress too much. Leveling routines are typically not as polished as end-game routines, so don't look for the perfect Leveling Routine - it doesn't exist and it will never play your character as well as you would. The basic philosophy behind leveling routines is to be compatible with all classes, kill stuff and keep you mostly alive.
You would do best if you help your Routine during the leveling process by choosing a Class Specialization with a lot of survivability and a Talent Build with a lot of Defensive options, or if such are not available, a ton of high-damage options. Heirlooms also help, especially in the 1-80 bracket, where your toon will be very fragile and the Routine alone will be rarely able to keep you alive. After 80, replace the 1-80 Heirlooms with Cataclysm Greens from the AH, as they will make your journey from 80-85 a breeze. When you reach 85, go to the AH and buy any MoP greens that are available, as they will be a massive upgrade compared to your Cataclysm Greens and depending on your realm each piece will cost you just a few gold. Should you fail to find what you are looking for at the AH, you can Quest or grind BG's to 87, then go to the Vendor in Pandaria and buy for pennies appropriate MoP Questing Gear.