Hello!
I suppose...let me start this off by saying my opinion is going to be very biased. Like Fonty says, you should really see for yourself if this game is for you. You're asking people who play PWO about their opinion of PWO, after all. I'm only going to answer the stuff that might not be immediately obvious.
PWO takes a different approach to development than other games. For community, the staff are generally transparent about design decisions, will chat with you ingame, and have organized change logs. PWO has definitely come under "New Management" in recent years and are much much closer to having a healthy and frequently supported Pokemon game than its past iteration imo.
PWO prioritizes quality over quantity, which means the updates go through a more meticulous/rigorous process. BUT, because the past-year's updates are carefully thought out and somewhat tested, features are not "taken away" after introduction due to them being broken/poorly planned, as other fanMMOs have had to do.
As for your other questions, PWO does not have character customization and staff are looking into a system for ability/nature modification. Whether that will end up as a sort of breeding system is yet to be known. Scamming is low, and we have a very strong anti-bot/anti-hack system; use common sense, read up on Pokemon rarities, keep records etc and you'll be fine.
I like to think that ultimately PWO will end up as the most balanced fan-game. This is primarily due to the PWO staff's high priority for balance and long-term planning regarding every existing feature with incoming updates. Butnosrsly just try the game out, see if it's your cup of tea.
If you want to see the game's progress in the past few years, check out these forum sections:
http://forum.pokemon-world-online.net/forumdisplay.php?fid=3
http://forum.pokemon-world-online.net/forumdisplay.php?fid=4
That should answer most of the questions that aren't immediately obvious by logging in for an hour. Hope that helps!
