I'll add my input to answer your questions:
WHAT MADE LIFE EASIER AS CELIAC: SUPPORT from others including a next-door neighbor whose husband is celiac, a local celiac support group (esp. the leader), THIS MESSAGE BOARD and my husband (after I finally told him what I needed).
HARDEST THING TO GIVE UP: Freedom to walk into any restaurant and order anything on the menu without worrying how it will affect me.
SOMETHING TO REPLACE WHAT I GAVE UP: A local totally gluten free restaurant owned and operated by a celiac who brews her own gluten free beer, makes a Chicken Florentine that beats the Coq au Vin I had in Versailles and fantastic gluten-free peanut butter cookies (as well as gluten-free versions of other things we might miss like burger, fish & chips, sandwiches, pizzas, cookies, breads, etc.).
TIPS FOR KEEPING ON DOCS FOR DX: ZIP. I gave up after my own PC diagnosed me with 'IBS' 7 years ago and recommended I follow the IBS diet which told me to eat more whole grains (esp. wheat bran) which made my symptoms worse!
WHAT ABOUT COMMUNION: I take the juice (wine) and pass the 'bread' plate, but we just pass the elements in our church now. 'So glad we aren't 'served' anymore, so nobody (except my husband) notices I don't take the 'bread'.
WORST THING ABOUT CELIAC: Being or learning I was? 'Sorry I forgot how you asked that question. WORST ABOUT BEING: All the excruciating pain I suffered and other confusing but less painful symptoms I experienced most of my life (I had 'symptoms' from early childhood which were misinterpretted by my parents and misdiagnosed by my doctors) BEFORE learning I had celiac. WORST ABOUT LEARNING: Fear everytime I had a gluten 'slip' (from mystery ingredients or cross-contamination) that I was further damaging my intestines which have suffered so much celiac damage for soooo many years.
BEST THING ABOUT CELIAC: Again I'll answer with being and learning: BEST ABOUT BEING: I'm a LOT more vigilant about choosing foods which are beneficial for my body, not just what tastes good and satisfies hunger, because longterm malabsorption has deprived me of vital nutrients and zapped my energy too long.

BEST ABOUT LEARNING: FINALLY an explanation for all those painful and embarassing symptoms as well as a treatment to resolve the pain and 'symptoms'.
I WANT TO ADD: I don't consider learning I have celiac diseasea burden, but rather a blessing. I'm SOOOOO glad to finally experience less pain (I went from excruciating to tolerable to no discomfort for short periods) so I can eat without fear that I'll hurt for the next 4-12 hours. I used to eat from pain of starvation (because I avoided eating until my blood sugar was so low I had to eat) to pain of dull bloating discomfort followed by sharp cramping pain. I LOVE knowing I can eat gluten-free foods without discomfort. Maybe people, who see their celiac diagnoses as a burden, didn't suffer enough pain to realize the benefits of going gluten free.