Balanced training method help

Hey there, welcome to the forums! I'll tell you what though: disregard the Balanced guide for now. It's old and quite outdated - it still works, but I've learned that the methods you use to raise an amiibo to Level 50 ultimately do not matter in the long run. It's what you do after Level 50 that counts. If you did want to go through with the training, you can just do it without the Heavy gravity setting. 

For Shulk, I recommend you put a priority on the Monado Arts. They're Shulk's main "gimmick" and are important to his success. Use Buster against your amiibo when he's at low percentages, Smash when the amiibo's taken a lot of damage, and Shield when you've taken a lot of damage. In general, your Shulk amiibo will prioritize Jump and use it whenever he's recovering: there's not much of a way around this; you just have to keep using Buster, Smash, and Shield correctly - eventually your amiibo will pick up on them. 

Something else you should do often is Counter. Shulk has the best counter in the game, and it allows him to eat "top tier" amiibos like Little Mac and Ness alive. As you train your amiibo, do not jump or use aerials. A lot of people have learned the hard way that being in the air will leave your amiibo open to attack and usually gets them killed. If you can teach your Shulk to use the Monado Arts, stay grounded, and play defense, you'll have a champion on your hands.

Before I answer your question, keep in mind that amiibo only use "true" combos - ones that cannot be air dodged out of - so, for example, you can't teach a Captain Falcon amiibo to use down throw to neutral aerial, because it's not a true combo. An example of something that is a true combo is Ness' down throw to forward aerial.

Shulk himself has no true combos, so when you grab him, use either a forward throw or back throw to send him over the nearest ledge. I do that with all of my amiibo, even if they do have grab combos.

Regarding the launch rate, keep it at the default one. Amiibo really don't learn combos at all, and I think that's the only reason you'd set the launch rate to 0.5 - all that will accomplish, however, is a confused amiibo later on.

I suppose I didn't go as in-depth on defense as I should have. Whoops. Basically, if your amiibo can perfect shield with high accuracy, it's going to be able to survive longer. If your Shulk can counterattack with a smash attack after perfect shielding, it'll be able to create opportunities where it can deal a lot of damage.

You can go into Games & More > Custom > Characters > Shulk to create a custom build that you can use. Give the build a piece of equipment that has the "Easy perfect shield" bonus effect. Once you get into a game, try to perfect shield as much as you can - if you do get the perfect shield you'll hear a "ping" sound. After perfect shielding an attack, use a forward smash (or an up smash if your amiibo is above you) and that's all you need to do to teach your amiibo to counterattack.

Playing defense might be hard to get used to, but it's now just a "way of life" for me. 

Also (sorry for the double post! xP), didn't the guide say that Fair and Nair were good approaches?

Hey, it's no problem!

Keep mirror matching him while playing defense, staying grounded, and using the Monado Arts, smashes, and Counter as I mentioned before. All the way to 50. By the way are you using equipment on your amiibo?