I've heard many people getting stuck on the flowers one... Funny because I was so worried about it being too easy so I tried to make it as difficult as possible to avoid that.
The two linked letters one I thought was so clever when I came up with it, but in practice people have just found it difficult and annoying, oh well.
In hindsight I could have made that section of letters much simpler to ease people into it a bit better.
The next section of puzzles is even less intuitive by the way, so I completely don't blame you for stopping at that point. I think that solving them may require somehow figuring out exactly what I was thinking when I came up with them.
Here are the rot13 solutions in case you or anybody else is curious though:
L: Lbh zvtug unir thrffrq gung gur nafjre vaibyirf sbyybjvat gur qverpgvbaf gung gur sybjref ner snpvat.
V znqr sbyybjvat guvf cngu cerggl qvssvphyg gubhtu... Gur cngu tbrf va n cresrpgyl fgenvtug yvar sebz sybjre gb sybjre, ubjrire lbh ner abg noyr gb qverpgyl sbyybj guvf cngu lbhefrys. Vafgrnq lbh unir gb xrrc genpx bs gur yngrfg sybjre nf lbh onpxgenpx nebhaq nygreangr ebhgrf gung lbh pna jnyx gb. Fbzrgvzrf gur yvar tbrf pbzcyrgryl gubhtu ebbzf jvgubhg gbhpuvat nal sybjref ng nyy. Jngpu bhg sbe erq-ureevat sybjref, gur cngu bayl geniryf nybat gur barf vg uvgf qverpgyl.
X+E: Gurfr nffhzr lbh unir fbyirq nyy bgure yrggref sebz guvf frpgvba (fb abg pbhagvat O) svefg. Fvapr lbh xabj gung E vf abegu bs X, guvf yrnirf bayl n pbhcyr bs cbffvoyr bcgvbaf sbe gur gjb bs gurz, naq bayl bar bs gurfr svgf gur X pyhr. Xrrc va zvaq gur X pyhr vf ersreevat gb ebbz nqwnprapl, gurer vf n urqtr oybpxvat lbh sebz qverpgyl jnyxvat nybat guvf cngu.



