So I'm trying to sell power. I have an abundance and the neighbor is a bigger city. Do I just need to wait or is there a bug maybe? Haven't been playing for long and started in 1900.

There should be a way to propose deals and not just wait for them to happen.

A few other questions:
-Does the music change to the ominous one depending on your budget or pollution level, or is that my imagination?
-Is there no newspaper like in 2k?

-Is technology always tied to education level here?
-When in general is it good to connect to a neighbor and is it ever bad?
-Are roundabouts useful?

To be able to be offered a power deal you have to run your power lines to the edge of the map and say yes to the connection.

That may depend on which game you are actually playing.

Yes that was the first thing I did. Playing Unlimited if it makes a difference.

Water--- impossible to maintain
Electricity-- the game keeps pushing you to build more plants and it can become a trap
Garbage-- not bad

Newspaper-- no

Don't know about music

Better IQ; more high tech businesses. But there comes a time when you get complaints about "not enough high tech jobs." Never could get that one solved. (IQ-- adequate schools and libraries; plus museums, zoos).

Roundabouts-- have to see the design of the City.

1)Did you pay for the connection?

2)If you use rail a lot then a roundabout will soon lead to complaints of overcrowded trains (having traffic stay on one line). I tend to use rails a lot and have only been able to avoid the complaint with parallel lines in residential and commercial areas. No so important in Industrial areas. Along with Bus Stops. (again not in industrial areas).
Bus stops work like a cab stop rather than a bus line. So keep an eye on whether Sims are actually using the bus stop. Sometimes sticking one in an residential are will be used a lot.

One of the Buttons has a series of graphs (health, aura, etc.) IQ is on one of those graphs.
PS. I used IQ. In the game it is EQ (Education Quotient). Also, the funding of education is important.

Yeah, there's the green arrow there. I did get offered a garbage deal after establishing a rail connection so that's good. Then the same city offered to sell me power instead lol. Trying another neighbour for power.

Thanks again. I have put some bus stops in residential areas as well as industrial ones which are almost on the other side of the map, with both rail and road in-between.

Good Luck and keep an eye on the bus stops (esp industrial ones). Unused Bus Stops can get expensive early on

PS
Connects = Commerce. So roads and rail connections (and an ever larger Port) = more dense Commercial areas.

I forgot to mention that you need a Mayor's House before any deal can show up from another City

I see. Well I do and did have that actually.

Your own city needs to be at less than 50% of electrical capacity before another city will offer a deal.

This is NOT a thing

Your current utilization of the capacity of the relevant kind of utility actually connected to the neighbor in question must be Less Than 40% to be offered to Sell your excess capacity

To be solicited to Buy, requires utilization as measured by the neighbor across your connections of Greater Than 80%

It equally is possible that your city as a whole be 99% utilized but an isolated Wind Power Plant happening to be connected to aneighbor but not your main grid can trigger a deal

The inverse is also true where your city-wide utilization is low, having plenty of excess capacity ubt no physical transmission from the majority of that capacity to the neighbor connection exists thus no deal ever gets offered

There's also a time variance of up to 6 Months from the time the conditions become suitable

Then there's the non-mechanical non-SimCity-specific general issue of real time gaming where counterintuitively slower game speed makes things happen faster because of less time passing between steps in the process, and clicks by the player No

just your imagination No

Meet and Ticker serve that same purposes in 3000 that news performed for 2000 and then some

everything in the Ticker is meaningful and useful just obfuscated and subjected to scrolling latency especially under faster simulation speeds If you mean Rewards and Opportunities then absolutely NOT, except in the case of the few Rewards explicitly rewarding Educational Quotient

If you mean Industry then yes

isn't simply a case of an increasing Educational Quotient yielding increasingly higher-technology/clean Industry though

Industrial Development can be considered among the primary thematic foci unique to SimCity 3000 It depends; the ultimate answer to everything! Yes

Transportation Connections to Neighbors are a legitimate destination which necessarily impacts Traffic densities and flow

Utility Connections to Neighbors can create annoyances of constant Deal requests There are no special mechanics for them if that's what you're asking

SimCity 2000 and SimCity 3000 scales' use tiles of edge lengths of 64m and only depicts Zones and Roads, abstracting Lots and Streets, where SimCity 4 has a scale that uses tiles of edge lengths of 16m and thus depicts both Lots in Zones, and Streets intersecting Roads

The difference in scale plus the difference in map sizes, which are quadruple both 2000 and 4 in 3000 are fundamentally what make 3000 more of a more macro scale grand strategy game whereas 4 and later, and almost every other city builder, are much more micro focused tactical games, where details like the type of intersection matter more