I looked the at the use of 感じる a few months ago. I came to the following conclusions:
The verb is usually transitive (他動詞) ; it takes を with a noun (including embedded noun phrases with の)but
It can also be intransitive (自動詞): Space ALC list it as both and give the example ~が退屈に感じる (feel bored [uninspired]).
It can also take と to mark a "quotation/sound or manner adverbial" phrase, in which case the と seems to follow a verb (and I think we can say 感じる here is intransitive).
- When it appears to take に, the に particle is actually marking an adverb. This happens with transitive and intransitive uses of the verb.
- It also communicates three different ways of "feeling".
I have tried to explain #5 below with carefully chosen examples of 1-4 which can be picked out with little difficulty:
I classify the three feelings as Physical, Emotional and "Spider" (because the last is somewhat intuitive, similar to the way that Spiderman can sense danger). Examples of each are as follows:
Physical sense (五感で刺激を受ける):
家が揺れるのを感じた|I felt the house shake.
Emotional sense (eg to be moved ⦅by⦆; be impressed ⦅by⦆):
その時,初めて母の愛を深く感じた|I had never felt my mother's love so strongly.
そんなにいい仕事をやめたなんて何か感じるところでもあったのですか|
Did you have some special reason of your own for giving up such a good job?
Spider-sense (eg to sense ⦅that⦆):
彼は生命の危険を感じた|He sensed that his life was in danger.
彼ががっかりしているのを感じた|I [was aware of / sensed] his disappointment.
彼は何かを隠していると感じた|I felt that he was keeping something from me.
The follow-up question to this explanation might be what is the difference between expressions taking と and を? Very briefly:
(i) Some verbs such as 思う always takes と (another example would be jumping to a conclusion, 早合点する)
(ii) Some verbs such as 忘れる and 思い出す never take と because you can only remember/forget facts not beliefs!
(iii) Some verbs such as 考える & 分かる take both because they can take two meanings: You can either just think (ie believe) or think about something (ie consider facts), either is possible.
感じる falls under category (iii), as can be seen from the examples above.