I agree with your broad conclusions on link development.
The future, in my opinion, is for VALID THEMED LINKS whether reciprocal or inward/outward only.
What do I mean by a valid theme?
(a) One which goes with the grain of Google's financial and strategic interest - so no reciprocals with 'locality-as-a-theme' websites as Google views these as open to abuse ie link swops between different types of business or amenity even if they are part of a local small-town network,for example.(Please refer to a recent thread headed Bad Neighborhoods)
(b) One which satisfies, and enriches, the experience of the majority of potential site surfers. The operative word here is 'majority'. Take as an example a commercial printing company. Owner, staff and a few others might regard links to the paper and ink supplier as part of a valid theme, likewise the professional association of which they are members. But Joe Public?
They would not find these links helpful.
They would appreciate links to page layout software, graphic designers, copywriters, anything which would help them decide on how to produce their brochure/leaflet/flyer,etc.quickly, cheaply and with the highest possible quality.
Google wants to reward sites which enrich Joe Public's experience. That's what it all about. The question is: will Google penalise the milder sort of bad or invalid theming or just ignore it 'neutrally'.
So if we accept this basic assertion for a moment,how does this effect the way we build websites for the future?
Big web sites will neeed to break their content down into sections all based around a sub-theme; and then aggregate their sub-themes into an over arching main theme. And cross linking between pages on different websites would be on a sub-theme basis. This would do away with a website Links or Resources page - which Google has in the past shown a disliking for anyway, I understand.
But, the really interesting development could be the rise of small 'commando' sites with a very clear tight theme acting as the mountaineers of the Serps.
Back to Basics, the subject of another recent thread, noted how many #1 positions were occupied by 'expert sites', simply designed with the minimum of graphics, quick to load, a lot of large HTML,deep rich content, masses of links to authorities and research style sites, and conveying a TOTAL committment to the interests of the user.Most of these sites have used no Optimization, as generally known, but quite by chance satify Latent Sematic Indexing.
In my view it's now better to have a number of small 'commando'sites to scale the heights of the Serps whilst, perhaps, in some cases retaining the graphic-rich content, the play value, and certain other features to sites which don't aspire to scale the heights but which are 'advertised' by their smaller brethren ie 'This Site is Sponsored by Poo-bah Widgets'
This is not meant infer all business/sites could go down this route;but the 'old' all-embracing multi-product/feature/service site may be giving way to a more segmented, tightly themed, variant.