1900x1989i will produce a perfectly good Blue Ray result except that, if you burn the BD disk with PE9 you must make sure you do not burn the disk at a speed higher than the blank disk is capable of otherwise it wont play in some players.

PE9 doesnt have the option of setting the burning slow so many people use another cheap program like Sony Architect or Cyberlink Power Producer to author and burn the edited file from PE9.

4x BD disks are cheaper but BD burners these days start at 8x.

Is your camera really shooting at 50 frames or 50 fields? These are different things.

In 50p and 50i there are the same number of 25 'frames" for both. They both have advantages and disadvantages for older TVs but they look identical if the picture is stationary.

The same number of pixels is shown in both every 25th second

As with film projection and old analog TV, each frame is repeated twice  (50 fields) to reduce flicker or 4 times with old 100hz Tv sets

50p means that a complete set of pixels is repeated twice every 50th second, frame 1 being the same as frame 2, frame 3 being the same as frame 4 and so on. A 100hz TV will repeat each frame 4 times.

50i means only half the pixels are shown every 50th second, each frame being shifter down by one pixel height so only half the pixels are shown at a time quicker than the eye can detect. Frame 1 contains line 1 & 3 and so on and frame 2 contaims lines 2 & 4 and so on.

With moving objects 50i can give a jagged affect to moving vertical lines if the TV set has a cheap or no processor to counter it but can also soften the "moving in jumps" effect when viewed at a further distance from the screen. Interlace (i) means only half the bandwith is needed so in TV you can have twice the resolution for the same transmission money.

With moving objects 50p can accentuate the jumping because each frame is more clearly defined. Usually a HD 50p picture is softer because a max of 720 lines is available as 100% more bandwidth is needed for the same reason.

If you examine old movies frame by frames you will see they made sure there was a blurring movement on all moving objects by having the shutter of the camera open as long as possible between frames. This reduces the "moving in jumps effect" when played back.

On the other hand if you shoot with a fast shutter so you can select freeze frames or with frame by frame animation , then you will get jumps on movement when shown at normal speed unless your TV processor can smooth them over by taking an average of pixels.

As an aside -

As an Australian that has grown up with 50hz Tv I never did notice the 50hz flicker except out of the corner of my eye where fast motion is more noticable. Many Americans who visit do see it clearly because they are used to 60hz.

In Australia & Euurope most people ran their old CRT computer screens around 70hz which looks completely flicker free to me.

I use a Panasonic TM700 and shoot sports at 1080p, then edit in Adobe Premiere Elements 9, and burn a normal DVD first. The quality of the DVD is acceptable, but not up to the quality of the original film clips. Then, using the same edited video that made the DVD, I burn a Blue-ray HD DVD. The final quality is almost as good as the origional TM700 clips. Amazing quality and color, although you need a blue-ray player and a 1080p HD TV to see it.

Thing is, Adobe Premiere Elements 9, COULD, let you assemble in 1080p, and burn a 15 or 20 min movie on a normal DVD burner, to then play it on a HD 1080p TV, because as Corel Video Studio lets you do just that, then Elements could also do the same. But the video editors don't want to give you the option.

I think they are short sighted to block this option because, as the quality of 1080p is so much better than 1080i, that video editors can't hold back this progress for much longer.