Let me start this post by making clear that all elite mark pops are force pops. Meaning you pop it manually. You don't need to sit and wait for a shout from a random player to know when an elite mark is up. So you can all see why radar programs are pointless. So please stop jumping to the conclusion that people are cheating/hacking. Maybe other players just know the mechanics better then you.
Now for the actual idea: How about some kind of "All points bulletin" that an elite mark has popped. Perhaps make it an FC buff that you have to spend points to use or something. Example: "The <insert elite mark name here> has been spotted in the vicinity of <insert area name here>!"
My FC mates have done a few elite mark runs using the information provided below:
All S rank seems to bel able to pop 36h after beeing killed or 24h after a miantenance
Middle La Noscea : Need to mine Grade 3 Lanoscea Soil (Node pop around 9 PM ET and need about 400 Gathering to mine the node) : Confirmed
Lower La Noscea : Will pop when night falls (Around 6-8 PM EST) during a full moon (Full moon last 1-4 Eorzea Days) : Confirmed
Eastern La Noscea : Chance to pop after heavy rain (Showers) : Confrimed
Western LaNoscean : Need to Harvest Lanoscea Leak (Node pop around 8 AM ET and need about 400 Gathering to harvest the node) : Confirmed
Upper La Noscea : Need to walk on the stone way with a Minion Out (seems to need at least 10 people walking) : Confirmed
Outer La Noscea : Need Alot of people to die over and over (Lots of deaths ) : Confirmed
Central Shroud : Need to rain at least twice in a row (Can't confirm if Mob will pop during 2nd rain or after 2nd rain)
East Shroud : Can pop after doing certain fates (exact fates unknown)
South Shroud : Will pop during one of the 3 New Moon Nights Confirmed
North Shroud : Need to Fish a judgeray between 5PM-9PM ET (Recommanded 360 + Gathering) : Confirmed
Western Thanalan : Need to Fish a Glimmerscale during Clear/fair weather recommanded 360 + Gathering : Confirmed
Central Thanalan : Need to cook something ) Still unknown
Eastern Thanalan : Need to spam Battlecraft Leves over and Over Confirmed
Southen Thanalan : Need to spam all the fates over and over : Confirmed
Coertas : Need alot of people to fall to 1 HP over and over again (Best way is to drop down a crevace) : Confirmed
Mor dhona : Need to dig alot of treasure maps (Not sure if alexandrite map works) : Confirmed
Source: Clicky Mc clickerson
Side note: As for the hunt marks not redering on your screen, please contact SE's tech support here.