Google Keyword Planner - Are its forecasts accurate?

[brightlife]

Hello, I am new to using Google Ads. I have several questions I hope you can answer. I put a Q: before each question.

I am looking at the Google Keyword Planner Tool forecasts.

Q: In your experience, are these forecasts accurate for:
Q: (a) Shopping Ads? Q: (b) Search Ads?
(the forecasts for the following factors)
Q: Volume
Q: Clicks
Q: Avg CPC
Q: Avg Position

For example, I typed in the following phrase:
Phrase: "alarm clock"
Max bid: $0.50
Timeframe: October 1-October 31

and the Keyword Planner Tool forecasted:
VOLUME: 823,000
CPC: $0.43
COMP: 0.46
CLICKS: 2,273
COST: $851.63

Q: Are these forecasts likely to be accurate?

My other question is this: I want to make sure I understand the role of the conversion rate for my store in the CPA.
Q: If my store has a conversion rate of 2%, that means I should expect 2 sales for every 100 clicks?
Q: Using the above example of "alarm clock" with a CPC of $0.43, I should expect that my CPA will be 50 clicks x $.43 = $21.50 CPA?

If I am calculating this right, then I need to set a sale price that accommodates a $21.50 CPA.

PRODUCT COST: $20.00
DESIRED PROFIT: $5.00
CPA: $21.50
TOTAL SALE PRICE: $46.50
This is horrifying because I do not see many alarm clocks I can sell where a reasonable perceived value
would be $46.50+ !!!! The CPA ends up cancelling out many of the products I would like to try selling!

Q: Are these forecasts based on shopping intent search queries only or do they include all manner of searches such as
"I hate when my alarm clock goes off" and "What is the loudest alarm clock?"
Q: If the shopping intent queries are mixed in with all these other queries then can I really trust any of these forecasts
since I won't know ahead of time what % are shopping intent vs % information intent?

I am using these settings:
Location: US
Language: English
Networks: Google
Timeframe: Last 12 months

I am sorry for so many questions at once. I will deeply appreciate your help if you can answer these questions for me.

Thank you!