According to a gunsmith I spoke with back when the BLR was new on the market, Browning "didn't cut the gears right", for the best leverage locking and unlocking the action. He had worked on several at that time.
Essentially, while the BLR does have a rotating bolt, and for pure strength is on a par with a bolt action, it does NOT have the camming power of a bolt action, and so loads that might cause sticky extraction are to be avoided.
In other words, stick with factory ammo, or handloaded equivalents, and don't try to get the absolute last possible fps from that gun and ammo.
I have one of the later ones (post 81?) that has the more flush magazine. Inherited from my father. It shoots well enough 1.5MOA or so, plenty good enough for anything bigger than varmints.
It does seem to kick more than my other .308s, but that's due to the stock design, and may not matter to you.
Trigger pull is a bit heavy, and I would call it only "fair", but again, good enough for the intended use of the gun. Because the trigger travels with the lever, the setup is difficult to get, and keep a really good trigger pull on. If you can live with it the way it is, I wouldn't tinker with it.
The other advice is good, don't take the gun apart more than absolutely needed for cleaning, and DON"T LOSE THE MAGAZINE!