Just a quick one for people that don't use the terminal, if you open a finder window and go to Macintosh HD/Library/LaunchAgents/ you can drag the "net.pulsesecure.pulsetray.plist" file out of the folder and move it somewhere else for safekeeping or delete it so it doesn't run on startup.
Sorry if this seems obvious, but it's for the less tech amongst us!
You can do the same with Pulse. PCS supports the IKEv2 protocol and we've had customers use that solution on Windows with success. The only downside is that there is no host check option when using the native vpn clients.
Just food for thought.
Also, it may be good to understand what the real issue is here. Is it that you don't want the client to load and show the splash screen (which is configurable) or is the Pulse Client causing some issue like an inability to connect to a network resource or the internet.