I'm a 10 year tw2002 noob. I played in the mid-90's...would get like 100k credits (no scripting), buy a good ship...die to mines (I never valued density scanners..I was 12 and stupid )
Is planetary trading (with a mobile/ambulatory planet) usually done as follows: Find port selling 3000+ Equip, Buy/Dump, move planet to port buying 3000+ Equip and negotiate?
If so..is there a good script out there to do this for me?..I've been doing this by hand..and while profitable (i'm playing good so PPT isn't cutting it anymore) it's a pain in the Butt..even using SWATH to find ports etc.
Or am I being completely stupid and is there an easier way to Planet Trade?

Never saw a Planet perambulate   ...standard TW vernacular for a movable planet is: Pwarp (Planet Warp, aka a 'L4' or greater.)
TWX Proxy. I'm guessing you're not using it. Get It.  Reconnoiter  www.grimytrader.com, search the script 'bank' for scripts. I would highly suggest Cherokee's Script packs.
If TWX is not for you, acquire Mind Dagger's script pack for Swath, it has a pretty good World-PTrade; Cashing Scripts, et al.
You should also visit http://www.navhaz.com, and click on TW-CABAL. Read up on MCIC. This will help you determine which ports to Upgrade in preperation of PTrading 32k, or 64k units of product (leaving out 'Red' oriented info). This in particular is the tip of the proverbial TW-Economy-Iceberg, necessitating TWX-Proxy --absolutely essential.
To answer your question. PTrading is negotiating with a Port, the Buying price of your product at unit levels much higher than what your, or any,  ship can facilitate. You *can* buy and dump product onto a planet and move to another sector to resell it. In order for this to be profitable you need to buy and negotiate costs of up to 50% of a ports 100% (maximum) unit level, and sell the bulk via Planetary Negotiation elsewhere. I have tried this once, and without utilizing MCIC, there is negligible profit when compare to World-Port-Pair-Trading --irrespective the Turn Base.
Therefore. In conclusion, I must insist that you pull my finger

One more noobish question. How do I add scripts to Swath? Assuming I download Mind Dagger's scripts (I will DL TWXProxy once I find a suitable primer on how to use it) how do I actually add them to Swath's script library (I have the fully registered version of Swath..but this is my  first time playing in 10 years).

You have to put them in the java file on swath, and point to them from the preference window, get it open, and go to the scripts, and set it to there, usually it automatically does it, you can also point swath to the twx proxy as well, if you have twx installed.

Doing a buydown-nego is much more turn efficient than a PPT. Think about it, you don't spend turns warping. If you're good at managing the fuel costs you can make this pretty efficient.

There aren't a lot of good public world trade scripts. Not that it'd be hard to write one, it wouldn't, there just isn't one because they don't get used a lot. Most people that do ptrade do it by hand.

If you can find a way to get Oz's scripts tho he has a ptrader in his. I think the manifest destiny pack has a pirated ver on it @ grimy trader.

Most people don't buydown and then selloff tho, just as is, instead they either add in a megarob after the buydown (makes it a lot more profitable) or they just nego off colo production.

Oz's oz-planet-trade-best used with ck_buydown and ck_planet_nego works for me for the general product sell off using un-upgraded ports. For games where I have upgraded the ports and have a great deal of product to sell off every day, I have a separate script that uses the ck_buydown and ck_planet_nego and I just input the list of ports to be used.  In the right circumstances I make lots of credits.

I use Swath and TWXProxy for this.

Cerne

I modded oz trader to accept a list of ports. I'd imagine w/ the built-in BFS it'd be pretty easy to write a ptrader.