Okay, firstly, I just want to make you aware of how bad format re-encoding is. Expect major degradation of quality.
Next, can you clarify, is it Region encoding (doubtful as you said you downloaded) or format?
Since you download, it will be region free, so what your saying is that your equipement is too old to support PAL? The reason I'm assuming its region free is because the first step in ripping is to put it through DVDdecrypter that removes macro and region coding. If for some bizarre reason the ripper hasn't done this, that's all you need to do, under the menu of Tools>IFO>Region patch. Or your dvd player can be hacked to region free see
www.dvdrhelp.com
However, I don't think its the problem.. is this your TV or your DVDplayer that's stoneage?
The answer to your questions is no, no, no. The problem is that your TV or DVD player is incapable of playing back the superior PAL picture format, not the disc. To convert from PAL to NTSC you've got a lot of work. You have to demux the video stream from the ISO, encode and degrade the movie to the older NTSC picture standard (smaller picture, poorer colour quality, higher frame rate).
To do this requires a lot of work, but you can find guides for this at
www.dvdrhelp.com , or
www.doom9.org . They take a long time.
Now, the best option available to you, is to locate the region bottleneck and replace it with better equipment. These days, DVDplayers can be unlocked to region free (see
www.dvdrhelp.com ) and because of this support both PAL and NTSC broadcast formats, so I'm guessing your problem is your TV that is incapable of playing back PAL footage?
However, shouldn't the disc work, but you get a distorted black and white image? If so, then the problem is you need a better TV.
So the short answer, if your setup is incapable of handling the superior PAL format, then there's no one click solution. Its not the fact that the disc is region encoded, its the fact it uses a better picture format to NTSC. Region encoding and format encoding are different things.