Princess Undine: it's a very difficult card, sometimes as hard as the lunatic version (Bury in the Lake). I recommend that you bomb it. If you really want to dodge it, try to move as little as possible, and move UP through the small-blue-bullet walls rather than waiting for it to wall you. The metal fatigue bullets actually aren't that hard if you don't move around wildly. You simply read it, and then dodge it (may require unfocus), and then STOP moving once you've dodged all the bullets cuz the aimed laser will come now.
Marionette: quite hard with Reimu, cuz you can't swing around the screen to misdirect the bullets. The thing to do is basically man it out at the bottom, dodging and shooting Sakuya as much as possible. At least you are using ReimuB, which means less dodging cuz she kills it faster. Also, rank can make this card very hard, so if you haven't died or bombed in a while, be prepared.
Scarlet Netherworld: I think you only have to dodge 1 wave of the criss-cross bullets. If you stand in the place where the first 2 bullets miss you, all the subsequent bullets will miss. Of course, the danger then comes from the vertical bullets. Don't psyche yourself into hitting them lol. Chances are they will just miss, and if they won't, you can simply just nudge a little bit.
Remillia's 2nd nonspell: aimed, spread, spread, aimed repeat I think.
