What Oro said about rewarding and not basic, having all the tools needed, etc. ^
Though Side-B/Blaster style of play can 'work' I still highly recommend avoiding it, almost entirely. Maybe not entirely, but almost... like, as much as you can.
I Power Shielding the first 2 ZSS Blasters (charged and uncharged) that came my way (as Zard) and it ended in a full stock. To this day, it's increasingly easier to do, and very unreliable.
The most reliable way I've been able to apply Blasters is uncharged quick shots when landing and someone is coming towards you from a distance. Using it when grounded when landing, but quickly and only when your opponent is anticipating a Side-B that you don't perform, so they try punishing.
Or something along those lines going through their head.
Otherwise, it's just too risky if they're not already in a disadvantageous position.
Side-B is nice, but I suggest using the 'presence' of the move, more than actually using the move itself. Does that make sense?
You have it, so use it, but only establish that it's there and you 'will' and revert to not using it. This presence opens a lot of room for you.
She doesn't need help against spacies. A single grab and she can just chase them, whether it's Dash > Dsmash/Grab or something fancy like Side-B/Dive Kick/Aerial>Regrab.
She doesn't need better approaches, she has a neutral-speed game with a grab that can catch anyone if they do nearly anything.
I think I would consider Down-B her saving grace. The offensive use when edge-guarding, or straight KO's, or mobility in all forms and situations.
I get more kills with Down-B than anything else, and suggest looking into applying it more, as there seems to be a lack of discussion about it in these threads.