If you can afford it getting guardrails all the way around will go a long way in keeping cars from making a nose dive.
There was a guardrail and clip pack (C8212) available a while ago that I really like as you can adjust how far out the guardrail is from the track: Directly attached, about 4 mm out and a good 7 mm out.
All new sport guradrails fit in the clips so even if you can just get the clips it can go a long way.
It has been out of production for a while though.
There are of course lots of guardrails and borders available that connect directly to the track. The "classic" borders that are the length of a half-straight are usually very easy to get.
The really old 60's style guardrails that are the length of a full straight are also quite common.
They are the thin, spindly ones in the picture ext to the "classic" barriers. I use those on straights where the chance of the car flying off are really low. They can be very brittle though and may need taping.
Actually all barriers and borders might need taping to hold in place.
Give that there are some tracks of the same dimensions and thickness made in other countries (Sp@in) there fences and borders will fit as well.
I think Slot Car Scenics makes a catch fence that is much higher. You might need to do that at the end of high speed straights.
Depending on whether you want to modify your pig pong table you can of course just get some wood and nail it to.....
As far as storage is concerned the original packaging is usually goo as it keeps the tires off the ground and protects from dust.
Any box will do but you should try to keep the wheels off the ground and they should be enclosed. A lot of people store them on their roofs.
Spare, older classic track can usually be cheaply bought and used for displaying.
Just some ideas!