How realistic is it that 7-8 factions are tracking outside the area where they were spotted? I mean some hate will go further but also think about if the factions have friends or enemies in other places.

To be fair - though there are that many factions, they're not all converging simultaneously. Many are watching, waiting - perhaps remaining neutral.. while others ARE actively seeking them out. That doesn't mean that finding the PCs is an automatic thing. They may never come into play again ... but they're out there for when the time is right. A couple examples:

• The Order - Actual fairly neutral - both enemies and allies in this group: A group that works in cells around the realm to hide a massive source of power, ultimately working to protect the realm. However - their motives are questionable. The party has actually befriended (and saved) some of the members, which (unbeknownst to the group) has prevented a lot of trouble... such as assassination attempts.
• Elven High Mage council. Interested in that source of power mentioned above - seeks to exploit it if possible. However, isn't necessarily working against the PCs, but is waiting (and following).
• Rival Pirate Captain - attempted to betray the group and failed. Now that crew is bound and the PCs have his ship. Not sure what's going to happen yet :)
• Two brigands - Early in the campaign, the PCs were jumped. 1 member of the brigands was killed. His Wife, one of the other two, still lives.