All roads to Narva (Estonia) are as good as anywhere in the EU.
Once in Russia, from Narva to StPeter and then to Moscow are generally good with some potholes and deformed sections but improve the nearer you are to big cities.
From StP to Mosc avoid the marked "new" road by-passing Novgorod to the east. It was less than half built when the money ran out. One carriageway graded but hardly surfaced, taking both directions of traffic. The other carriageway virtually non existant - good for off-road practice except it's not open! Far more comfortable going through the town, and probably quicker too, as all the lorries crawl along the by-pass. Unless things have changed since last July, that is.
Apart from Borders, Roads Police spotchecks occur from time to time - generally documents checks. No hassel if your docs are in order. You are on your way within a couple of minutes. Expect to be stopped on average once every few hundred miles on main roads/entry to big cities. Its a game of chance - having foreign front number plates will attract more attention than usual, as you are more interesting that the beaten up old Ladas held together with duct tape!
Radar speed checks often in villages along main roads - note the town name signs, which indicate an automatic speed linit. Often these extend a long way either side of the built up areas. Oncoming drivers often helpfully warn of radar checks by flashing lights. But if not, the going rate for bribes is about 500 rouble ($20 - £10)
No experience of camping. Should be OK in those parts off the main roads and out of sight. But what do I know....