I am losing the will with my Cricut machine so posting on this forum is my last hope (and my Cricut's saving grace!)

I am trying to cut what I would think is a very simple design but for whatever reason my Cricut will just NOT cut to the measurements specified and every single cut is DIFFERENT!!!!
PLEASE can someone help me out because it could be a very simple change I need to make or it could highlight that my Cricut is 'faulty'.
I have attached the 2 .svg files I am trying (desperately) to cut. I have drawn up my designs in Inkscape.
File - Inkscape invitation base:
This is meant to be 29cm x 12cm with scored lines to make the size fold inwards like 'flaps'.
First issue: it doesn't cut this file to the correct measurements
Second issue: some scoring lines cut right through and others are perfect
3rd issue: when I fold the 2 sides inwards, they don't meet in the middle
4th issue: once the 2 sides are folded in, the 4 corners are not all the same
5th issue: the points of the 2 sides are not a sharp triangle point but a half-hearted (and never the same) rounded point
File - Inkscape invitation top:
This is meant to be 14.5cm x 12 cm and is meant to fit into the centre of the Inkscape invitation base.
First issue: this BASIC rectangle shape DOES NOT cut to it's measurements!!!!!
What am I doing wrong with these designs?? Why does SCAL not cut these to exact measurements??
I wasted LOADS of paper and worked well past midnight last night trying to get these 2 'simple' designs to cut perfectly.
These are for wedding invitations therefore need to be PERFECT.
If anyone can help me I would really really appreciate it. Let me know if you don't understand anything or need more information.
Thank you in advance
Jaime
*a very annoyed and frustrated SCAL/Cricut user*