3 questions

1.) Leasing is when you choose the "purchase" option for a building or ship, and instead of the full price pre-selected option, you choose one of the three options below it that has a reduced initial cost, but with a per turn payment for X amount of weeks. For diplomacy, I think you're referring to Tribute. I know AI's can pay tribute as I've seen the Galactic News message indicating it, but I don't believe a player can give or receive per turn or per year tribute. The only way this occurs is if they call you up demanding cash or if you call someone up trying to extort some.

2.) Morale is significantly affected by population. Your homeworld has max 16 billion. It will mostly have a crappy approval rating if it sits there with the full 16 billion on it. If you build a ton of morale buildings, you get less and less from them. It's best to make transports and move colonists offworld for invasions/resettlement and not waste more than 1 maaaaybe 2 tiles on morale structures.

3.) Uhh can't help you there. Not sure what you mean.

1/ Got it. But the "tribute" column at endgame statistic still 0, even I paid them, they paid me,...

2/ My other planets got 20.00 bill. pop., and those citizens' morale are still better than my home world with 16 bill. I built on my homeworld 3 morale improvements, the others with 20.00 have 3, too, no bonuses.

3/ The view screen in diplomatic screen?

1/ I get the same results all the time too.

2/ I sometimes get a planet that does like my capital, but usually other capitals that I conquer through influence(and have 16bil pop) are happier than my capital

3/ No clue what you mean. I play terran a lot.

3/ You NEVER get it when playing Terran. Play another race and speak with the Terran, you will understand.

The Terran leader viewscreen doesn't have animation. It's just a picture.

3) Every race video gets stretched in the diplomacy screen when using wide-screen resolutions. Some are more noticable than others. I agree, it's terrible, Stardock needs to fix it.

2) Don't put farms on your homeplanet or other buildings that increase your maximum population. This goes for conquered homeworlds too. (Nothing wrong with buildings that increase your population growth though)

Virtual Reality Centers and low taxes are the best way to get morale up. You will need about 3-4 VRC's for every 15b population depending on other modifiers. It's a good idea to have one planet as your transport builder and population center.

Not...exactly what I meant...

Anyways, aren't hotsprings of the Torian better than VRCs?

It probably has something to do with the new Terran leader portrait that was introduced in TA. No idea how to fix it, though, sorry.

After 20b though, those VRCs mean less and less. Back in DL this may have been true.

Except the Terrans don't get those. You were specifically talking about the terrans. I'm sorry that I didn't specify the VRC's for the terran. The hotsprings are less maint. with a 20% morale boost. VRC are 40% morale boost with 7 maint vs 3 maint. on the HS.

After 20b the amount of VRC's goes up AND you will need a low tax rate. I had a PQ 24 planet in one game. I thought I'd try maxing out the population (terran). This is what I had.
PQ 24
Pop 27b Morale 94%
VRC 15 (two were on 100% modified tiles, blue teardrop)
Tax rate 15%

I got tax rate 58%, morale 100% with 15.00 billion pop. PQ 23, 2 VCRs. That's the result of 1 fully upraded Morale Starbase + Planetary Adaption . Some other techs that improve morale...

It was a crisis that all planets in some sectors got quality of 5. I built weather controls, terra formings, improve PQ to 12-13. Now, total pop. were about 800 bill. Morale 99%. Income...7000, tax rate 58%

Thala's homeworld joined my empire, it has 24 bill pop, morale about 96% (I built almost all slots with VCRs, aboult 10-15 VCRs). All others have 10%.
Another planet with 100% morale and 22.00 pop with only 3-5 VCR (no bonuses)

300% farming bonus is totally useless, or dangerous. With a fully upraded farm (and a food distribution), max pop. is 52.00 bill. I don't know how to deal with it. I think star dock should remove it, and make another better bonus (say 300% morale bonus)

It's usually better to keep pop a little lower and around the same level for all your planets and build Stock Markets instead of morale buildings. Especially with the huge maintenance cost of VRCs. Tax money raises with the square root of population (on each planet). So if you go from 16b to 25b you only get 25% more money from that planet.

Yes, but you can build two 6000 troop transports for invasions to gain even MORE bc!!!   

But wait... that 25% is good enough. You also have better planet defend, better stand in UP vote. If you have Morale Resouses (mine as much as you can), you can tax them so much -> $$$$$$$$$

Remember the crises I said before? now, I have 105 planets, total pop. count as Trillions :)) I have 3 fully upraded Morale mining starbase now (just continue playing a while before). tax rate about 60% and averange approval is 100% (note that there is 1 Thala old homeworld with 24.00 bill pop.)

That and you had said in your post that you wanted to try and max out the population. Maxing out bc income wasn't the goal you posed.

Just pointing out an optional use for large population planets beside the bc factor. As Greatergood34 pointed out, those planets are very hard to capture! Of course if that planet is under assault, you need to re-think your strategy on where to place your defending fleets!   

I was talking to Greatergood who didn't say anything about maxing population. So I gave him advice on how to improve his morale and econ situation. Sure huge pop planets have benefits, but they also have disadvantages which very often outweigh the pros. Innefficient use of building space, money, production and turns for example.