this was my first thought too - certainly amongst the first things that needs to be checked (it is relatively easy to check).
or it would be a clutch issue itself (worn out disc, etc).
but i think we might be askew here. in reading your post again, you say it is hard to downshift into first while rolling. ummmm, that is not the best thing in the world to do. while first does have a synchro, shifting down to first is not a great thing - if you need to do it, be sure to rev match to help out your synchros/blockers (if you are driving over 5 mph and try to jamb it into 1st at 1K rpm, it aint gonna like it).
for reverse grinding, put it in a forward gear first, then reverse. this slows the cluster down so you dont grind the straight cut reverse gears.
good luck.