Help with placements/shape overrides?

[aboweFIS]

I made a content type called "SingleTitledText" for fields I found myself recreating over and over:

I'm using it in BagParts in other content types, but I don't always need ALL the fields. For instance, in the following, I only need "Heading" and "Detail Text" to display as options, and I want to hide the others:

I think I can use placements to show/hide the fields I need but I can't get the file name correct (or am otherwise doing something wrong).

Also on these I'd like to remove the option to add more than one which I think I can do in the BagPart.cshtml View, but again, I can't figure out the correct template name to give it.

I've studied Templates and have watched the different Dojo videos but it's still clear as mud. Note I'm coming to this as a front-end designer/developer so it's been a bit of a challenge! Thanks in advance!

[Piedone]

Since it seems to me you're just bundling a few fields together in the type, the easiest would be to just use different types for the different use cases. This works if the distinction for "I don't always need ALL the fields" is different parent content types. If not, what is it?

[aboweFIS]

Okay so you're saying I'm going about it the wrong way. I thought this is exactly why I'd use alternates and placements but it sounds like I am just making it harder on myself. I'll go back to the drawing board. Thanks!