You might be correct in your assessment, however, if there were to be an assassination attempt on the Pope I would bet my life that it would be perpetrated by Sunni muslims and certainly not hezbollah or syria. The closest allies of the Alawites are the christians in Syria, Assad would not damage his christian support because that would spell his doom. Hezbollah would not attempt a similar move because they have nothing to gain and are very organised in keeping their members in check.
The threat comes from a lone gunman type scenario in which case a sunni muslim extremist fits the bill perfectly. That being said muslims in lebanon know not to target christians, hezbollah didnt even try to enter christian areas of beirut when they did their little takeover and retreat, because they knew it would escalate, the christian civilians are very well equipped to take care of problems themselves and hezbollah know this. Last time a church was attacked by palestinians, the christians ignited a civil war and did quite well eespecially since their only ally for part of the time was israel, with the rest of the world looking neutral and all arab countries financing muslim militias to murder christians.
And yet the bottom line is that he is risking his life, and were he to be killed, the tragedy would go far beyond Lebanon. There is so much that he is doing and needs to do in the world, for which he is uniquely prepared.