On the tensioner rail, try the technique (on my site) of placing a long screwdriver through the part-inserted lower (and only) pivot pin to stop the tensioner rail falling through. Insert the rail until you feeel the screwdriver, then remove the screwdriver, drop (!) the rail a little lower and push in the pivot pin.
On the others, yes, it is easy to drop them. I used clean gloves to hold the top of the rail (no grease, better grip than naked hands). Really not that risky but you have to concentrate hard and have absolutely no distractions.
An alternative is to use a pair of fine nosed locking pliers, but I feel less comfortable with this approach.
Finally, if you focus on inserting the lower pins in the three flat rails first, the upper pin female fitting on the rail is a natural place to run a piece of wire or string through to be absolutely sure you do have something to grab if you drop the rail - that would be the safest way.
Can't swear to it, but I believe '84 and on had the full electronic timing.