just because you assumed Yoda was flat out lying to Luke about Han & Leia dying on cloud city doesnt mean he was. remember Luke asked him if they will die when it first came up and Yoda closed his eyes and looked to the future and said something along the lines of how he didnt know.
also, what did Luke actually do when he got there to save anyone. all he did was almost get himself killed and have Leia RESCUE HIM. Yoda wanted him to stay and finish his training so he would be able to succeed in destroying the Emperor and Vader when they first met. The there is another hope comment was saying that if he goes now he's not ready and he might die and not be able to destroy the Emperor and Vader so hope would be lost, and Yoda said that the other (who later became Leia) was still an option.
But didnt someone here once say that Leia & Luke werent originally gonna be brother and sister? so if you want to call it a plot hole (or poor planning/change in character/plot flow is more accurate) why dont you bring that up. Im not saying there are no 'plot holes' or more like inconsistancies in the OT, but most can be explained just as well (if not better) than the inconsistancies caused by the PT which should have never have occured because there was already plenty of 'fact' set down in the OT that could have easily been referenced/adhered to.
Maybe the radar just pickes up ships, how do you know it differentiates between TIE fighters and Star Destroyers. with all the cloud cars flying around maybe he missed it. or maybe because Han is somewhat cocky and had thought he outsmarted the empire he didnt think to check the radar while he was trying to get landing clearence. Maybe the cloud car shot at him to distract him so they had time to move the TIE's and Star Destroyers out of his sight.
Cloaking device. I believe the line was "No ship that small has a cloaking device" Keep in mind this is said by an Imperial Officer who is also probably cocky because he is the commander of a Star Destroyer of the Galactic Empire. Maybe power consumption of the cloaking devices would be too much for a normal ship that size. maybe there are civilian issue cloaking devices that you cant get put on ships that small for 'legality' reasons, ie the Empire doesnt allow it. but it never said they couldnt have one on it, just no ship does. But we all know Han has made plenty of modifications to the Falcon, many that im sure the Empire or any officials would even think to look for on his ship so why not a cloaking device. Because some Imperial Officer said so? So far in the films the Imperial Officers havent really giving me much of a reason to have the most confidence in them.
assuming radar works like it does here, its also very likely that while in a busy city a radar is a bit crowded and kind of hard to pick out an Imperial Shuttle landing. Plus, the shuttle might be 'drowned out' or all together hidden due to its positioning in the city/hangar bay/landing area.
remember it was you who said you would be willing to provide answers/reasons for the plot holes in the PT. well, you have answers/reasons provided for what you find to be plot holes in the OT but your refuse to accept them. thats your choice, but it doesn mean they arent there and more likely/logical than the ones for some of the PT errors.
if you want i can provide explanations for most of the other points you mentioned.
-Darth Simon