First Numenorean contact with Middle Earth

"It was six hundred years after the departure of the survivors of the Atani [Edain] over the sea to Númenor that a ship first came again out of the West to Middle-earth and passed up the Gulf of Lhûn. Its captain and mariners were welcomed by Gilgalad; and thus was begun the friendship and alliance of Númenor with the Eldar of Lindon."

Numenor colonies?

They visited the "primitive" Men residing there, and had some impact, but did NOT make any permanent abodes of any kind. And the emphasis that their early visits were in effect unarmed had quite an impact when they ran into the dark foe's minions in their early exploration.

The time they spent with these tribes didn't really make them colonies, only places to stop and rest and resupply (at the generosity (or not) of the locals).

Resources, especially trees were definitely (and I believe clearly stated by Tolkien) and issue, and thus the stripping of the treelines along the costs of Middle-earth, to be shipped back to Numenor.

In fact, not entirely. You have this another quote

 "They (the Númenóreans) ranged from Eressëa in the West to the shores of Middle-earth, and came even to the inner seas; and they sailed about the North and the South and glimpsed from their high prows the Gates of Morning in the East." (People of Middle Earth 149)

This is no support for havens in these remote regions. It only tells that the Númenóreans went there. IIRC the quote's context is the age of exploration when the Númenóreans began to explore the world as allowed by the Ban of the Valar. Note - they *sailed* there. They did not *settle* there - or made havens.

During such voyages, there is absolutely no need for own havens. Either they visit havens from men living there or they made landfall in a cozy little bay to re-provision themselves (e.g. by hunting) or repair their ships (by chopping wood). Both these are described in UT as well:

"But for long the crews of the great Númenórean ships came unarmed among the men of Middle-earth; and though they had axes and bows aboard for the felling of timber and the hunting for food upon wild shores owned by no man,..."  

UT. Description of the island of Númenor

In essence, the quote does not speak of settlements (only long voyages) and the real-world explorations, it is IMO highly unlikely that the Númenóreans set up harbors or settlements wherever they went. They simply explored the world - nothing more (at least at this time). The later colonies are highly unlikely to have been located in the Inner Seas or beyond. The western shores (from north to south) were the territory for Númenor's overseas possessions.

Let's examine the case of all the conflictual colonies:

Hithlond : a little Haven in the North, probably built in an association with the locals (Ulshyans).

Balkuloni : the same than Hithlond, a small Haven shared with locals of the Sea of Ormal

Sakal an-Khâr : this is the most important colony of Numenor.

Azrathani : a small outpost, still shared with locals of Shay.

Anarikê : an important colony of Numenor, also in the Inner Sea.

All of these colonies have to be mentioned in the Numenorean essay.

The later colonies are highly unlikely to have been located in the Inner Seas or beyond. The western shores (from north to south) were the territory for Númenor's oversea possessions.

Again, this is an interpretation, not a direct affirmation from a quote of Tolkien.

Since we begin with 2d Age 1000-1200, this essay should not burden itself with the way *how* these people got there. It is only important to know *that* they are there. Of course we have to include wide wild and unpopulated areas where mankind is still far from being the "Master of Middle-earth"

 For the level of civilisation, maybe a general note on plausible Technology  levels of Middle-earth Men before they are met by the Numenoreans would be sufficient. If necessary, maybe also pinpoint some civilisation centres on the map, to show areas where the Numenoreans might fight people with a higher degree of civilisation (find organised kingdom and cities).

Though these centres of civilization should be rare around 2d Age 1200.

One or two at the most. And even until 2dAge Endorian civilization should be lagging far behind Númenor. Not only in terms of "Tech level", but especially in form of organization, sophistication etc.

Powerful or even moderately powerful Endorian realms should be the exception rather than the norm in this time.

 The exploration of the Inner Seas occurs much sooner - SA 1004 with  Soronto, in the lands of the Chyan Empire and Olyas Kriis.

-Fortunately, we have a quote for Tolkien that gives a hint:

-"The first sign of the shadow that was to fall upon them appeared in the days of Tar-Minastir, eleventh King. He it was that sent a great force to the aid of Gil-galad. He loved the Eldar but envied them. The Númenoreans had now become great mariners, exploring all the seas eastward,..." LotR. Appendix A

-Interestingly, it is the time of Tar-Minastir (or a bit before him) that is associated with the far-flung voyages into the east. This would limit former times to the exploration of the western coasts.

The quote is relative to "all the seas eastward". This is why I placed the "start" of the exploration (i.e. the entrance into the Inner Sea) in the period immediately before, so that, in Tar-Minastir's time, his son Ciryatan would bring his ships to the eastern seas, beyond the Inner Sea.

 “Other protected havens may have survived along the coast, and greater colonies in more remote lands, such as the Inner Seas or the East, may even have suffered little or no damage. Those realms who survived were greatly modified though (when they accepted the mixing with natives). Others, like Umbar, maintained for long the legacy of the Black Numenoreans, and in some cases, of the Mulkherites. Some other colonies of the Far South did not survive the first millennium of the Third Age."