I've worked for honda as a tech for 12 years now and have changed 100's of belts, many on the D series and B series engines,I can count on one hand how many have needed water pumps or have had failed water pumps on a d series and also the same goes for the tensioner. Yes they are a interference engine unfortunately and the belt should be changed every 75k or 7 years. Hope this helps Also the crank bolt is normaly around 180nm, a realy good snap on gun will get them off but make sure there done back up just as tight. We have a special tool at work which is a massive hexagonal tool that fits inside the crank pulley it's self ( if you look at it it'll have a hexagonal shape in the middle) thats what holds the pulley in place so you can undo the bolt......I'm sure the tool must be available by now to buy good luck!