Don't know Flash, so I really can't compare.
In Vue, you can use different units in the timeline, like in any 3D app: seconds, frames and SMPTE (hour, minute, second, frame)
Default is seconds, but you can change it to the units you want by right clicking the timeline and choosing the " show time as" options.
If you want a ball at zero (frame or second), load the ball when the cursor on the timeline is at zero.
Next, you want a square at 4 seconds, right? Drag the cursor at second number 4, and add your square. Next go to 8 seconds and delete the ball.
Each action is recordeded automatically IF and only if you have automatic keyframing on, if auto keyframes isn't on you need to right clcik the timeline cursor after the action was created and choose "keyframe, add keyframe, and choose what kind of keyframe you want (all properties, or other available choices depending on the action that happened)
Best is to have auto keyframing on, so you don't need to record each keyframe (with the possibility to forget to record a keyframe), of course it will add keyframes to all properties, which may not be needed, and may slow down processing the animation.
To enable autokeyframing, make a long left click or a right click on the keyframe icon next to the timeline (it looks like a key).