Hi Jkpita! Well...I hope you have good knee-pads! Cold winters huh....I wouldn't know...Fargo only got to -30 this morning; and I think Bismarck, ND got to -35+!!! So, if Fargo hits 100 this summer, I can honestly say...where else on "G*ds-green-earth" can you have 130+deg. variation in ONE year...??? (I can't understand why there's movement in your structure?!!?) ;-) Crikey!!! Seriously though, * I'd lightly scrape along the cracking/lifting areas with a putty-knife to see how easily it pops off. * You've GOTTA get rid of loosely bonded layers, or your new paint will literally pull-off the old. * I can't remember what it's called, but find some real dense/hard foam. Somewhat like the foam-insulation sheets. * These can be trimmed to make a "sanding-profile" block that will follow your trims' curves. * Or, just use flexible sanding-sponges. * If you have sharp ridges, just use your putty-knife carefully to press the paper along these ridges, to help bring back any "definition-lines". NOW- When you're sanded-down to smooth/sound trim...AND all dust is removed... * Haul out a good brush and primer! * There's NO reason to use oil for ANYTHING here. * 123 primer from Zinsser, C2-One by C2 are two very good ones. Ask at your stores what their best Latex primers are. * If you're REAL fussy, you can lightly sand these primers, but you've gotta wait 1/2-a-day or so b4 they're dry enough to sand nicely. Now for the joint-caulking! DAP has some good paintable caulks, but ask at your stores, Dynaflex 230 is a great all-around caulk; Polyseamseal is too; and, inquire about their "painters-caulks" too. * Big-Stretch brand caulking is good too, IF you have unusually frequent movement. * Paintover times vary here...read the tubes. ONE TIP: Cut a SMALL opening, 1/8", and PUSH the gun away from you when applying. This motion gets the caulk into cracks better, instead of "barely sitting on top". * Then, use a wet finger, damp sponge, or other tool, to smooth off your bead. >>> Some painters prime b4 this caulking-step, some after. I'll completely defer to them!!! >>> For filling outside corner wood-mitre's, use a wood filler that hardens, and can be sanded/primed/painted. Caulk is OK for inside-corners. FINALLY... You've got beautifully cleaned, de-flaked, sanded, smooth, primed, & caulked (whew!) trim THAT WILL HOLD & DISPLAY YOUR TWO TOPCOATS OF PAINT BEAUTIFULLY!! (after all this...don't skimp on the Finish-paint OR the brushes!!!) Option- try adding some of XIM's Latex Xtender for more open-time when painting. It helps leveling too. Faron

You have bigger issues here with visible hardie board that is now sitting in a mud bed and going to be a serious wicking issue. Seams are not taped/thinset. Very novice errors and not suprising based on your other issues. You dont have A professional tiler on your project im afraid. likely more errors we cant see, Simply put, in the Pro tile world its already A full tearout.

This is why you place a continuous shim on the countertop that is the thickness of the grout lines, lay tile, grout, pull the shim, and fill the gap with color matched silicone. You have too small a gap to be filled with enough silicone to expand and contract, therefore it will always be an issue.

Carpenters don't caulk stuff. Painters do. I imagine sink installation contractors have caulking expertise, too. Your siding should have been completely primed on all sides and any cut edges should have been primed or sealed prior to installation and certainly prior to application of any caulk. If your corner boards are, in fact, treated material, you may have trouble getting paint to adhere well.