Sensing thoughtcasts that happened recently (not sure if this would be easily codable or not)

This could be either a learned ability, much like backtrace or a spell ability, if the person were able.

It would require a min circle of probably 50 or 60 at least plus thoughtcast, seers etc, there would be some check involved if the subject were resisting.

Also it would be nice if Moon Mages could sense such spells as Riftal summoning and Shade watch mirror on others when we perceive them.

A locate specific nearby objects spell might be useful as well.

A way to combine your beam with others for greater effectiveness, or to use the beam of another possibly if you outclassed them and/or had their permission, might be beneficial.

Moonmages can sense watchers in an area by PERC WATCH. Whether it be via Distant Gaze or Mirror.

We can sense if someone was RS'd by PERC them, but can't sense Seer's on them.:
>per oli
You perceive Holy magic clinging to Olitai.
The following magic is on Olitai:
Riftal Summons (which should last about five roisaen)
Olitai has no spell prepared.
Roundtime: 3 sec.

>>Sensing thoughtcasts that happened recently (not sure if this would be easily codable or not)

I think this would be really neat. Could be location based (sensing if a Thoughtcast was sent/received recently in the location you're in), or person based (sensing if the person sent/received Thoughtcasts recently) -- though I'd recommend only getting knowledge of the message if you specifically perceive the person. This would be so there's a very clear chance for the target to spot you trying to spy on them.

When perceiving a person, there could be varying degrees of success, from "a Thoughtcast was received," to picking out just some of the words, to getting the full message -- also with more skill one could see further into the past and pick up multiple Thoughtcasts on the same person. Difficulty maybe based on the mana put into the Thoughtcast, or possibly a WvW type check depending on whether the mage is trying to hide the Thoughtcast?

>>A locate specific nearby objects spell might be useful as well.

What kinds of objects? Like, the Crossing temple? It might be neat to cast it on certain big landmark areas just to spy on whomever is in the area.

>>A way to combine your beam with others for greater effectiveness,

How could you increase a beam's effectiveness? You mean, make it easier to gate to...?

Using the beams of others might come in handy in very specific, limited situations, but not a bad thought.