Hi Satman68 and welcome to the site
A1 With T&G you have to glue it and it will take longer to do the job. It is a cheaper option and i would advise going for a click version. If you have to take the floor up for any reason it is a lot easier. You can get a mid range version which is a click but once it's clicked you should not pull it back open. I have found this to be a bit of a pain when your cutting the boards to fit certain areas because you really need to cut it right first time. If you can afford it go for the one which you can click apart if you need to.
A2Again you find the more expensive versions more hard wearing. It should say what it is suitable for and a guarantee should come with the product. Make sure you follow the guidlines so the guarantee is viable.
A3Yes, with it being a hall way i would run it down the hall and not across because it wont look right. Start where you have the straightest run and get the first couple of runs down first.
A4You only have to take 1 length of skirting off when you are leaving all the skirtings on and cutting the skirtings with say a buscuit jointer, to slide the lam under it. You then need to take the one length off to put the last board down.
A5Yes you will have to cut the bottom of the arch's etc. Just a cheap saw with no back plate will do fine. Screwfix sell one which will do the job ok
A6Yes, again this is an easier option. Make sure you leave a good expansion gap and get quite a large quadrant type beading so you can leave a good gap. This is then fixed to the skirting boards and not the floor which allows the floor to move.
Think ive covered everything