I could build a third edition bard* to be entirely a melee character with minimal focus on supporting the rest of the party (TWF and Snowflake Wardance to kick things off). Doesn't mean that therefore a bard character needs multiple abilities on par with what anyone else can do; they're going to lose out on proficiency if you give that sort of breadth.

It would be better to start with a set of abilities that's balanced without actually crippling being useful, then make up a class, than to try and pick abilities to match a 'best-of' selection from D&D.

*Also, homebrew doesn't count. Most of the bard list is support-based for a reason. They're also behind wizards and so forth for spell progression.

[hr]

Your list of abilities, broken up:
Combat training (rusty, but there)
Invisibility
Magic Blast
Stun
Sleep Gas
Speed Boost
Healing and Stamina Increase

Plus a poison dagger. It's... rather overly versatile? You've got a few things that help others, but you're pretty frontloaded on sheer offence.