The modern goalkeeper must be able to use his feet -not only the hands- and qualified enough to move around the penalty box when required. Anyway, the goalkeeper is not there to avoid goals only. Today's goalies are also field players. In fact, at professional level, any modern team has a specialised Goalkeeper Coach, usually an experienced and former goalkeeper formally educated and who has the mission to pass all the secrets of his profession to the new generations.
On a personal note -for the sake of helping to put things in perspective-, i want to share a real story from my childhood. It happened during mid 70's, when the elite football stars weren't as well paid but, instead, they were still able to walk around without being so mobbed like today, thanks to zero internet, globalised Mass and Social Media and/or predators telling you "i gotcha" with a simple smart phone's click. Light years from all of that.
Anyway, my dad used to be a very close friend with some of the professional players of my favourite team, Santa Fe, in Colombia. I remember, before the games, the goalkeeper used to have a chat with my dad, telling jokes and mucking around to kills the nerves, while waiting for the kick-off.
Well, in one occasion, almost at the end of the season, they were chatting as usual, having some coffee in one of the corridors, playing cards and, wait for this, smoking cigarettes! Suddenly, the Club Manager showed up from nowhere, looking for the goalkeeper who, timely alerted by my dad, hid his cigarette into his tracksuit pants. Yes, ouch!.
Then, the goalie and the Club Manager left the scene to start the warm-up for that Finals-Match-Decider. My dad dad just winked at me, like trying to hose down the incident. However, i just kept that memory as one of my most "treasurable" displays of unprofessionalism.