You may be starting those cucumbers to early. I dont know when you can plant them out, but 3-4 weeks is the longest you really want to have them in pots. They are susceptible to lots of fungal diseases and will also stunt easily if you keep them in pots to long. Most people have to do some transplanting/potting up. You will get better with practice. I start them 2-3 seeds in little 3oz plastic cups in a domed tray, them divide them as soon as they get their first true leaves. At that size the roots havent developed much so its easy to pull them apart with out damaging them. If you really want to avoid transplanting at all, plant 2-3 seeds in a 4" pot, bag them or saran wrap them and if all three seeds germinate just take scissors to the two smallest weakest seedlings.

From my past experience on just a few items: tomato: 4 weeks (otherwise, they seem to get too big) basil, sweet: 6 weeks rosemary: 10-12 weeks (slow growing and slow germ) cilantro: 12 weeks (because they like growing in cold weather, and then they bolt come June)

Ottawapepper is right on. If you do this you should not loose any plants. I could help to keep them out of direct light for 24hrs to prevent any shock but other then that you should be fine.Lots of people just spread seed in a tray and transplant to cells after the come up with little or no loss.Done it many times , In fact did all my peppers that way last year with great results. The paper towel method I used this year made it easier to supply heat in a small aria but other then that both methods gave similar results. Peppers are very forgiving when it comes to transplanting. I hate to cull a perfectly healthy plant, no reason to.

I like all of your methods; Used all variations depending on conditions and circumstances. At one planting this year i have planted a few flats with seed rows oriented the longer direction of a 1020 tray, a few with seed rows oriented in shorter crossrows and one 48 cell tray with a few seeds of a different variety within each cell. Keeping good records and mapping each tray is important if you want to distinguish varieties and keep track of germination rates. I only caution those who use this method to allow older seed a few extra days and often it works better to group newer and older seed so you don't need to transplant individual rows (or cells) out of sequence. Planting to larger containers is often dictated by space under lights. I ran out of space under my 26 shoplights and , as of yesterday , all of my first batch of tomatoes are moved into a greenhouse. Half of those will go into the ground of a high tunnel in a few weeks, a few will be potted up and eventually sold in gallon pots or larger and the rest will be recycled. I would not suggest that everyone follow my methods but when any single potted plant needs water more than twice a week it is time for me to repot. Even a greenhouse can run out of space quickly if you have a lot of plants in larger pots.